Authentication Of People


Jeffrey S. Jonas

For NJIT ECE699: Information Assurance

Dr. Manikopoulos






Editorial note


Writing in the first person is usually shunned in technical writing, but the textbook _Network Security_ by Kaufman, Perlman and Speciner makes the topic much more enjoyable by telling jokes and personal anecdotes.  This paper similarly conveys meaning and shares real experiences in a friendly and informal atmosphere.


                                                                                                                                                    I.     The 3 main elements


Authentication of people (users, humans) has been done for centuries with passwords, tokens, secret handshakes, etc.  The 3 main elements are

1.       What you know

2.       What you have

3.       What you are



                                                                                                                                                         II.    What You Know

That is something that you have memorized: a password or PIN.  Or secret/private information such as mother's maiden name, nickname, club password.


There are many problems with memorized phrases

·         People tend to choose weak or easy to remember passwords

·         Passwords are easily compromised by just one utterance or observation

·         Passwords are often stolen from users by spying (shoulder-surfing, keystroke logging) or attacking weaknesses at the authentication server (stored in insecure files)


Sadly, many systems encourage people to use weak passwords.  A recent example: I just received a replacement credit card for one that expired (which is a rather weak security system too: credit card numbers are easily stolen so the expiry, holder's name or address is often used as a secondary identifier, but those are also easily stolen or deduced.  So credit card companies now print an additional number on the back of the card that is not embossed nor on the magnetic strip.  But of what value is that measure once the additional number is compromised, such as a "phishing" fake internet site?)  I was asked to create a 4 digit PIN, but it only accepted 01-12 for the first 2 digits since they not only recommended that I use someone's birthday as the pin, the entry system ENFORCED it!  I was then transferred to a human to enter my PIN, a human "white spot"!


I have resorted to circumventing the NJIT mandatory password-changing system because I forgot my new "clever" password several times now.

The NJIT system

·         Forces the user to set a new password after a certain number of days

·         An ordinary user cannot set the password again for a few days (although an administrator may always set the password again if it's forgotten

·         Disallows reusing the 3 most previous passwords

Since I can't remember such temporary things, I'm forced to choose weak passwords, or write them down.


                                                                                                                                                          III.   What You Have

A photo ID is well understood by people, but it's not machine-readable.  Machine readable or useable ID is usually an index into a database for the rest of the information, such as an employee number or credit card number.  That is made machine readable by

1.       Barcode

2.       Magnetic stripe

3.       Rfid

4.       SecurId

5.       SmartCards


A.       Bar Codes



Ordinary barcodes are good because they're easy to print and machine-readable.  Barcodes are on nearly all store products because it costs nothing additional to print on the label/container and it allows unambiguous identification of the item for checkout (which is fast thanks to laser scanners and accurate thanks to self-checking codes used in creating the barcode).  Barcodes are often generated as needed, such as on lottery tickets so winning tickets are automatically identified.  It's now common for people to print barcodes at home. lets you print postage yourself, and many store web sites offer bar-coded coupons and promotions which are printed at home and brought to the store for scanning with the purchase.


ID badges often use barcodes for the employee number mostly for the convenience of not needing to type it into a timeclock or door lock.  When I visited an office at the World Trade Center, a digital camera at the security desk took my photo and printed it on a one-time-use ID card with a barcode that activated the required turnstiles and doors for me to get to my destination.


Ordinary barcodes are vulnerable to photocopying!  The Pathmark supermarket allows me to scan my own items at the “express" checkouts (albeit with camera and human supervision), but I may not scan my own coupons: they must be handed to the attendant because too many people were photocopying coupons or vouchers where copies are not valid.


Infrared barcodes is the countermeasure to photocopying.  The equipment for reading IR barcodes is identical to the visible light scanners; they simply use IR light emitters and sensors.  The obstacle to deployment is the need for special paper or an opaque barrier over the regular barcode.  That way the stripe looks like a totally black band under visible light but I-R differentiates the stripes from the background.


A slight tangent: barcodes are not a new invention!  Here's a 5th century Irish barcode.  This is a "ogham line" showing all 25 "letters" of the Ogham alphabet:


This relates to the security because it's a method of secret writing!  Long ago, watermarks and secret writing were used to qualify documents, or secretly mark people as troublemakers.  Barcodes and machine-readable codes might be used in similar ways to hide messages from the bearer.


B.       Magnetic stripe


The magnetic stripe is ubiquitous since it's inexpensive and has totally displaced punched cards.  It's trusted for fare cards, credit cards, ID cards, etc.  But it's vulnerable to erasure (by magnets), alteration, forgery and duplication.


C.      RFID


RFID (Radio Frequency identification) is a contactless way to read an ID from a tag. Sensormatic's anti-theft tags are the most well known.  The US Military is using RFID to track inventory since it allows reading information from boxes deep within a palette (no more labels falling off or being too dirty to read).  Stores such as WalMart are aggressively pursuing RFID but the cost is still too high, keeping barcodes the primary method for tracking items.


Contactless ID cards are popular because they don't have to be worn visibly and the readers have no moving or exposed parts.  But there are privacy concerns because there is no off switch or notification of activation.  Microchipping animals with a low range RFID ID is now required by the European Union for pets traveling across boarders.

According to


Animal health and welfare

The Pet Travel Scheme (PETS) - Advice to UK veterinary surgeons in GB:

·         European Regulation 998/2003 takes effect on 3 July 2004. It sets out the rules for pet animals travelling between European Union (EU) countries and into the EU from other countries.

·         Microchip identification: We recommend that the microchip conforms to ISO Standard 11784 or Annex A to ISO Standard 11785. If it doesn’t, it may be impossible to read it when the animal is checked in another PETS country. The owner is then required to provide a microchip reader to enable it to be read.

·         To travel from the UK to another EU country, an animal must, in this order, be microchipped, vaccinated against rabies and issued with an EU pet passport.


See also:

In many countries (e.g. Australia, United Kingdom, Norway, Sweden), microchip identification and registration is mandatory for international pet travel purposes.


D.      friendly RFID: The Active Badge System


Many of the concepts used for electronic badge systems have been embraced for beneficial uses by the UbiComp (Ubiquitious/Pervasive Computer) movement.  UbiComp is more than just the evolution of the man/machine interface; it is teaching computers to work in a more anticipatory and less intrusive manner.   Instead of waiting for a command to turn on the lights, a "smart room" senses not just that a person is in the room but WHO is in the room and set things to their preferences.  As people enter the room, the room atmosphere automatically responds, trying its best to anticipate their needs and desires.


Andy Hopper et al. were the first to explore contactless ID cards (using IR, not RFID) to provide the person's location in real time.  This ubiquitous computing experiment explored desirable uses such as finding co-workers within the office and phone calls automatically following you.  Some areas were intentionally NOT monitored and there were ways to turn off the badge to respect privacy.


Another example from Professor Quentin Jones' UbiComp class: a health club used such a system for the background music.  As people entered the club, they used their ID cards to activate the door.  The music in the workout room changed according to the people in the room to meet their mutual needs.  Each person has a music profile that they set and may alter as desired.


People tend to understand the difference between place and space and behave accordingly.  The same church room may hold funerals and weddings yet people behave differently for the circumstances.  Teaching that to machines has proven difficult.  Consider cellular phones.  They cannot currently sense when it is inappropriate to ring out loud.  Some places have resorted to jamming cellular phones entirely because there's no universal method for silencing them.  Asking patrons to turn off their phones (or set them for silent alerts) does not generate sufficient compliance.  Perhaps when all cellular phones have a standard wireless interface such as Bluetooth they will also honor standard commands such as "silent mode" from a transmitter in the room, which is activated when appropriate.


What security folks call tokens, UbiComp calls phidgets or tangible bits [lutz03].  Instead of walking up to a keyboard or sensor, people handle physical objects that are sensed and tracked by the computer.  "Digital Chopsticks" allow people to point to each other's display (hand held PDA, laptop, etc), pick up and move data as if it were physically picked up by the chopsticks.  This is much more intuitive than clicking and dragging things to icons which must first be linked to the other person.


At Linux Expo 2003, IBM demonstrated the security features integrated into their ThinkPad laptops, making it harder for thieves to simply take the data from the hard drive or use the stolen computer.  The authentication allowed adding PCMCIA cards for SmartCards, fingerprint scanning and a proximity sensor.  Like an active badge, the wearer has an RFID badge that participates in logging into the system (remember the basics: it's not just WHAT YOU HAVE but WHAT YOU KNOW: an ID or PIN is still essential lest someone steal the card and impersonate you). If the wearer is too far from the system (the distance is adjustable) then the screen blanks (for privacy) and the input devices (keyboard, mouse, touch screen, etc) all lock until the person returns.


A friend told the story of the time he interviewed at the NSA.  Whenever he entered a room, "RED BADGE" was announced (apparently meaning "visitor with no security clearance").  The sound of many cabinets and drawers being closed and locked instantly followed.  Had visitors been issued an "active badge", then only systems within range would automatically blank their screens and systems further away would automatically warn the user that the system will blank soon if the guest walks too close.


Combine these scenarios: what if my photo were taken upon entering the building (such as the security system the World Trade Center used) when I was issued a temporary/visitor's active badge.  If the facial recognition (or other) system later determined that I was a possible bad-guy, then my location in the building would be instantly known by the badge-sensors.


E.       Delegation: it's not who you are, it's who you're working for


In the identification, authentication, authorization triad, tokens are an authorization device.  A token is granted after passing authentication and grants the bearer certain permissions.  When visiting an office, the front desk authenticates that I have business there and grants me a visitor's pass.  That is my token to proceed.  Tokens may be virtual too: at an internet cafe, I may be given a temporary password to use the computer.  Some tokens are not linked to a specific person and may be handed to others and the permission or privileges are transferred to that person.  This is often desirable to allow temporary access to some facility that is normally not accessible (such as the key to the locked bathroom).  Tokens (or tickets) are a vital link between authentication and authorization as in voting systems.


F.       Voting systems


Voting systems are a unique environment.  The person must be identified and authenticated as a registered voter, but the voting must be anonymous, irrefutable, unalterable and auditable.  And each voter may cast only one vote.  The current system of signing the logbook and getting a ticket to proceed to the voting machine is a deceptively simple and straightforward method of achieving all the identification and authorization requirements.  Identification and authentication occurs when I present my photo ID at the registration table and sign the logbook.  My signature may be compared to my voter registration card for further authentication, but it also leaves evidence that I was there in person (nonrepudiation), and prevents me from voting twice since I can sign in only once.  I am then handed a ticket that authorizes me to cast one vote at the voting machine.  The ticket is an intermediate step that separates authentication from authorization and allows me to vote anonymously.  It an elegant system because no step can be removed.


The Florida presidential election demonstrated serious flaws in low-tech ballot systems, so new solutions are urgently sought.  All electronic systems are being rejected due to lack of safeguards, public review and lack of a verifiable audit trail. is a good example of a solution that offers an unalterable paper audit trail.


The accompanying CD contains many comp.risks digests [RISKS].  Of particular interest are the news stories this week from California, where the Diebold electronic voting machines were decertified and not valid for elections due to lack of any meaningful audit trail and an inexplicably high error rate, as well as lack of trust in the programming used within the machines.


G.      Weaknesses


All these systems have weaknesses:

·         Passwords/pins are guessed or shoulder-surfed

·         Barcodes can be photocopied

·         Magnetic cards can be “skimmed” describes a clever ATM device that use WiFi to transmit the card data and even a camera to see the PIN entered on the keypad.


H.      Surreptitious identification


Despite the advantages an active badge system provides when it benefits the user, there are nefarious uses for tracking people, vehicles or items, particularly when the person is not aware of the surveillance or cannot choose to decline participation.


·         The Digital Convergence CueCat barcode scanner was given away for free by Radio Shack, Forbes magazine and others.  The alleged intention was for people to scan the barcode from advertising or products and get to the related web page.  The company is out of business because of a flawed business model: they spied on everyone using the barcode scanners to create a database of interests and never disclosed that intention to the end-user.  Each scanner has a unique ID number and encrypted the scanned barcode to force the user to send that data to Digital Convergence's server to map the barcode number into a related URL.  It is not known if everyone received the same reply, or if your profile steered you to different web sites (i.e.: people with profiles indicating wealth would be directed to web sites featuring the most expensive models).  Happily, the barcode scanners are now ours to keep and there are many web sites showing how to defeat the serial number and there's even a contest to write the shortest program to decrypt the output so it's useful by itself.

·         Wireless cards can be read without permission or action on the user's part.  The German store "Metro" placed RFID in the customer loyalty cards but failed to disclose anything about their existence or intended use.  Since they can be read from 10 feet away, sensors at the door could take attendance even if you don't buy anything.  Sensors around the store could monitor where you tend to dwell, regardless if you actually buy anything. documents how it was revealed and the store's immediate withdrawal of the program.

·         Embedded serial numbers are in computer peripherals, thus enabling "spyware" to track you from the computer parts, not just the system as a whole.  But such information is also useful for tracking one's own inventory, particularly for large companies.

·         Walmart was exploring the merits of RFID tags replacing barcodes on all items. They're in a position to force all their suppliers to use RFID or not get stocked in the store.  People are deeply concerned about their privacy, particularly since the tags may be so deeply embedded in a product that it cannot be removed or deactivated.  Happily, the incentive is on hold because RFID tags are still too expensive (despite many clever fabrication techniques such as using printing methods for making the antenna instead of foil or wire).  And there are countermeasures for RFID: place the item in a properly shielded bag.

·         When facial recognition systems mature, you can be identified without your knowledge or consent by a remote camera.  Wearing dark glasses or large hats helps.


I.         White spot elimination


A weakness of many systems is the "white spot": the point in the system where the information is not protected and is vulnerable to spying. Simple passwords are vulnerable to being observed and re-used (playback).

A One-time pad prevents that, but few people can memorize anything random enough to be secure.  Token devices such as SecurID allow the user to enter the response using any numeric input device (keypad, touch-tone phone) via an insecure channel because the value is valid for a short time, cannot be reused, and the sequence cannot be guessed.  Pirate ATMs and hardware that records all of a PC's keyboard strokes are now common, but properly designed security devices encrypt the data right at the source.  Bank PIN pads don't transmit the data in the clear but are encrypted right at the keypad (the keypad controller needs to be initialized with a session key, it's not merely read like a standard keyboard). Similarly, secure input devices such as hand scanners and fingerprint readers must communicate securely to prevent replay attacks at the communication link.  SmartCards have no white spot (except for the initial programming and manufacturing phase) so they may actively participate in standardized secure communications [rfc1824] [rfc1875] [rfc3193] [rfc3457]


J.        SecurId


RSA SecurID is a token: a device that looks like a calculator or digital watch and displays a time varying number.  When combined with an ID or PIN, it forms a one time password.  The server has a matching algorithm to verify the user and corrects for clock drift since the token works stand-alone.  I think of it as a secure hash of time and password.


Advantages of this system

·         No special equipment is required to use it: just a keyboard for entering the magic number

·         It thwarts replay attacks: even if the reply is captured it is valid only once and for only a short time (Kerberos uses a similar argument for why ticket theft is not such a problem).


The disadvantage

·         The server must be accessible in real-time for validation

·         One token per person is required, which is expensive


K.      smartcards


Smartcards contain a processor and nonvolatile memory so they perform dynamic data processing capabilities in addition to data storage.  The chip is so small that it's often embedded in something larger to make it easy to carry, such as credit card or key shape.  Unlike memory cards, it actively participates in the secure conversation from the host, so even eavesdropping cannot clone the card or reply the transaction.


I am an advocate of SmartCards.  See [jonas03a] (on the accompanying CD) for an introduction to SmartCards presented to Professor Jones' class. In [jonas03] (on the accompanying CD) I propose a SmartCard based system for personal ID addressing privacy issues described in [HILTZ03].  Instead of granting access to all information in the card, information is tagged with access levels: PRIVATE or PUBLIC.  The cardholder must actively participate in retrieving PRIVATE data to grant permission (although an escrow mechanism is possible for emergencies such as accessing medical history during an emergency).  I also recommend an audit trail in the SmartCard itself, assuring a checks-and-balances system so the card bearer may review who accessed the card, when, and what information was requested.  Despite SmartCards being programmable and alterable, the data is trusted because it's signed by a trusted third party similar to a certificate.  An X.509 certificate easily fits into a SmartCard's NVRAM with room left over for much more user data.


American Express' Blue cards are SmartCards.  They offer free readers for home use on your PC (USB or serial interface) so properly programmed web sites access the SmartCard directly to prove that the person at the keyboard is the card bearer since the card MUST BE PHYSICALLY INSERTED into the reader.  Sadly, they withdrew support for "Private Payments" (a one-time-use account number was generated using the card in the card reader, thus allowing one transaction but preventing abuse of the account as could happen by disclosing the permanent account number).


During a class discussion of key management, Rajat suggested keeping all one's passwords and account information in one file and encrypting that, so only that key needs to be memorized.  It's the electronic equivalent of placing all your passwords and secrets in a safe and only having to remember the safe combination.  Apparently the American Express SmartCard has that application already. According to


ID Keeper is the FREE Web tool only for Blue – that stores your Web information right on your Smart Chip.  With ID Keeper you can get to your favorite sites, shop, and manage your finances with high speed and security.


Target stores have already given up on their virtual-coupon program.  Since I, and none of my friends have ever heard of the program, I fault their inability to inform customers of such an innovative program!  Target issued SmartCard Visa credit cards with the store logo.  The intention was for customers to shop online and instead of printing bar-coded coupons (yes, a valid use of on-demand barcode printing), a SmartCard reader on the PC stores the coupons on the person's Target Visa

SmartCard so they were automatically applied to the purchase when paid using that same card!


I am extremely discouraged by the shortsightedness of American companies already withdrawing support from a SmartCard infrastructure.  It is a very worthy technology in which European nations are heavily investing because they know it'll reduce fraud and allow new features that will encourage acceptance and consumer confidence.  Had American Express (which tries to differentiate itself from other credit cards by specializing in traveler's needs) teamed up with New Jersey Transit and installed SmartCard readers in the TVM (Ticket Vending Machine), then I'd faithfully use my American Express card for all ticket purchases because inserting the card would automatically identify my preferred language (English) and my most likely purchase (round trip ticket Newark to Elizabeth).  There would be no need to navigate 6-8 menus every time to buy the same tickets that I usually buy.  Even if I choose a different destination, the menus would know to start in English and "choose a different destination" would be the bottom choice with my usual choices above.


Referring back to IBM's secured ThinkPad laptops, there are several security products for laptops that use SmartCards, either via a PCMCIA reader, or self-contained in a USB key-fob.  Vital parts of the file system depend on the presence of the key, else the data on the hard disk is inaccessible.


Back to the SmartCard technology itself: the SmartCard is a computational element of the protocol, not just a storage device.  Think of all the diagrams with boxes and arrows back and forth for getting a certificate, or answering a query to prove one's identity.  The SmartCard is the piece of equipment participating in the protocol, so there's no white spot.  Private keys remain secret to the SmartCard because the code that uses it also resides on the chip.  There's no way to get secret information out of the chip.  It's used to participate in protocols, but never directly revealed.  When properly implemented, this makes SmartCards impossible to clone.


Satellite TV receivers use SmartCards for authenticating that the user is a valid customer and authorizing what channels they may receive.  Unlike cable systems where a reverse channel allows the cable operator to read the converter's status, satellite receivers are totally passive.  There is usually no link from the subscriber back to the provider (except for services such as internet or phone service which are intrinsically bi-directional).  The cards are now available on the black market for receiving "free" cable TV due to a theft of the programming codes.  The SmartCards were not cracked to achieve the cloning.


Despite industry reluctance, SmartCards already deployed

·         In cellular phone SIM (Subscriber Identity Module), the permanent ID is protected, but the phone list, user preferences, calendar, etc are stored in it too.

·         Vending machines use prepaid "stored value" cards (the laundry room in my apartment building too!)

·         American Express's "Blue" card has both the magnetic strip and a SmartCard.

·         Military: ID smart-cards augment dogtags, used for authentication and multi-level security access.  The U.S. General Services Administration [GSA] is fostering the use of SmartCards.  A survey of Federal Smart Card Projects [GSA04] seems to show acceptance and successful deployment even for non-active personnel (such as Veteran Administration Health Administration benefit cards).


SmartCards pose ethical, privacy and security concerns:

·         Does the cardholder have the right to examine all the contents of the card?

·         Is each content provider required to disclose the data, when and how it's used?

·         May we administer internal data similar to the way web browsers have "cookie" control?

·         Will all smart card applications be bound by rules for privacy, security and disclosure?


                                                                                                                          IV.   Biometrics: proving what you are


People are remarkable for recognizing friends and noting imposters.  Teaching that to machines has proven extremely difficult because they cannot correlate enough information accurately.  Recent techniques are:

1.       Handprint

2.       Fingerprint

3.       facial recognition

4.       eye scanning (retina or iris)

5.       Voiceprint

6.       Signature


A.       Biometric timeclock


This clever device still requires your ID (note the keypad for ID entry and slot for ID card) but uses your hand's unique geometry as a secondary identifier.  The database continually updates your profile to allow for aging and follows the changes in your hand over time.  The reason for the secondary identifier is to thwart "Buddy Punching" where the first person to arrive punches in all their friends and the last person to leave punches out all their friends, thus falsifying the hours actually spent on the job.  But it's more than just a time clock: it can operate doors, and even display messages for the person clocking in.


The IBM Kingston NY museum displayed their early timeclocks.  Photos showed huge timeclocks with paymasters supervising each employee punch in and hearing the bell ring ONCE to verify the punch was completed. (Some were huge drums inside a locked box but rotated by a huge dial to the employee's "clock number". The paper on the drum had one line per employee with the time stamped left to right.  That way only the paymaster could access the paper and nobody could alter it).  Trying to punch in someone else ment pointing the dial to the other clock number and ringing the bell again which is easily caught by a watching person.


Some places tried using the door-access card for attendance on the premise that you have to walk in, but most doors allow exit without swiping the card.  The result is recording only arrivals but not departures.  Manhattan offices tend to have turnstile-type entrances so everyone must use their card to enter.  But it's natural for people to "piggyback" and enter a plain door once it's opened.


Since timeclocks are rarely supervised anymore, other methods are used to prevent friends from clocking in others.  Some require the person's ID card for the magnetic or optical stripe (common in supermarkets and stores), but combined with biometrics such as handprint reduces abuses.


B.       Fingerprints


Fingerprint scanners integrated to laptops were discussed in the active badge section above.  My cousin Lynda is a cardiologist.  Her office computer uses fingerprint scanning, as mandated by the privacy and security policy of the insurance companies.  But that fails to take into account an occupational hazard: scrubbing for an operation is harsh enough that the scanner does not recognize her fingerprint by the afternoon!


C.      Facial recognition


A Google search for "face recognition homeland" found 5,000 hits.  The good news is that many universities are getting funding for creating new, reliable facial recognition systems and many bright people are finding creative solutions.  The bad news is that some companies have already failed by rushing to implement facial recognition systems in airports only to find that the technology is too premature for any effective use at this time.  Failures included

·         Not recognizing known terrorists.  Face angle and lighting seemed to create too many differences for the system to compensate.

·         Taking too long to screen each person.

·         Presenting too many possible matches to the human operator.  5 or fewer possible matches is reasonable, hundreds is not.


In [SCHNE03] [CRYPTO] Bruce Schneier discusses real world needs vs. the systems implemented and how they rarely match.  Many companies reacted to 9/11 with security measures, which are mostly ineffective, and a waste of time and money.  He revisits the pillars of security by evaluating real world systems for

1.       What assets are you trying to protect?

2.       What are the risks to those assets?

3.       How well does the security solution mitigate those risks?

4.       What other security problems does the security solution cause?


Applying that to a facial recognition system with 99.9% accuracy (which no real system is yet to achieve) shows that it's mostly ineffective because

·         It only detects known criminals for whom useable photos are available

·         The false alarm rate is too high.  Harassing innocent people takes time and uses resources better used elsewhere.  Scanning 10 million people would result in 10,000 false positives.  Scanning everyone at a football stadium would create 75 false alarms per game and one real terrorist every 133 games.


What is the cost of a false negative: granting a known terrorist entrance.  Perhaps nothing: there's no guarantee that he's there to do anything malicious. Perhaps everything: if he's there for malicious purposes, but some secondary screening is needed to determine that: is he carrying a weapon or something totally inappropriate for the occasion?  Sadly, such screening failed on 9/11 since the terrorists did not use any weapons on the "watchfor" list.


What is the cost of a false positive: detaining innocent people.  Besides hurt feelings, it could lead to massive resistance to the system, particularly if patterns of discrimination are reported.  It also consumes resources to process each person.


Some systems are "closed loop" and learn from their mistakes.  There are many cases of people who are constantly harassed because their names are too close to suspected or known criminals.  Issuing them a "It's not me!" ID card has a problem: the known criminals will forge them for themselves!  It's up to the system and/or the operators to compensate for this (without introducing too many loopholes) else the system will be mostly ignored as "advisory".


D.      The future as we saw it


Science fiction movies portray alternate realities where technology allows constant surveillance of everybody.


The science fiction movies "Gattaca" and "Minority Report" are similar in their depiction of a near future where everybody is under constant surveillance.  In both movies, the main character/hero/protagonist circumvents the security system to prevail.  Happily, their goals were for the common good, as opposed to glorified villains/criminals.


In Minority Report, retina scanning is the primary means of identification to the exclusion of all else.  The hero gains a new identity with an eye transplant, but saves his old eyes to regain his previous authorization.  He was falsely accused of a murder he didn't commit while the creator of the crime detection system commits many murders and remains undetected because he purposely created loopholes in the system so he was above observation, review or suspicion.  The lessons are very valuable for today's security:

·         ALWAYS use multiple measurements to verify identity

·         Over-reliance on one technology or implementation leads to a monoculture where one attack will always succeed [thus all the worms/viruses for Microsoft products]

·         Security via obscurity ALWAYS hides flaws [thus the public peer reviews of cryptographic systems and open-source operating systems]

·         Everyone in the system is accountable for their actions [from the sleeping security guards to the director creating policy loopholes]

·         No person, place or thing is above accountability, audit or inspection

·         A checks-and-balances system is essential for all levels and scopes: from the reliability of individual components to the overall system preserving people's rights [an example from recent news: the U.S. is accused of denying the prisoners detained at Cuba's Guantanamo base of "due process".  This contradicts our intention of allegedly defending the Iraqi’s rights to a democratic & representative government when we're violating our own democratic process].


In the movie Gattaca, the DNA scientists are above reproach, so when a baby is born the DNA analysis is used to predict the child's anticipated aptitude and health.  Despite laws to the contrary, a caste system results with "valid" people getting the desirable jobs solely on good DNA expectations and "invalid" people as janitors for life.  There is no appeal process or method for re-evaluation based on what you actually achieve.  The hero had the aptitude and physical endurance for space missions but was forced to cheat and circumvent the unfair tests to reach his full potential.


The authentication systems were extremely thorough by testing anything containing DNA: blood, saliva, urine, hair, skin.  But there were secondary matches on face photo, height, need for corrective vision, any handicaps or abnormalities.


His methods were clever technical and social engineering:

·         Fake fingerprint and blood-bladder beneath it to pass the daily fingerprint and blood tests just to enter the building

·         A bag inside his pants for the random yet incessant urine tests so even the donor's urine was the correct temperature

·         Constantly cleaning his work area and leaving skin and hair from his assumed identity.


As the murder investigation increases, the screening tests heighten due to the diligence of the detective:

·         ONE of the hero's hairs was too close to the murder scene.  It was collected and identified, but linked to his previous identity.  So the game is for him to keep his new and previous identities totally separate despite all the opportunities for even a single hair or saliva to correlate his previous identity and his current location.

·         When blood is drawn under observation from a vein, he can't fake that, so he creates a diversion and switches sample vials.

·         At a police roadblock, he refuses the throat swab (which he cannot fake) with a blood test from his fake-finger-bladder.

·         When the night club is raided, he has no choice but to beat up a guard and flee.  Low tech but effective!

·         When he's not prepared for one last urine test, the technician passes him anyway because his son too was deemed "invalid" so he was a silent partner all along due to his hidden agenda.


Both movies exemplify how people circumvent even the most technically advanced security systems, particularly if there are sympathizers due to flawed policies.


In the TV series Space 1999, the Comlink was a videophone, communicator, door key, and multifunction terminal.  That classifies it a token type device.  One can hope that it recognized the user in some way so it does not grant full access to anyone who picks it up!  Cellular phones are now close to that: they have high resolution color screens, cameras, keyboards and because their SIMM SmartCard is considered a secure form of identification, it may soon operate vending machines and act as a key.  Unless a PIN or password is required, it's hard to prove who is using it!


E.       Other Biometrics


Phrenology is the study of the conformation of the skull based on the belief that it is indicative of mental faculties and character.  Phrenology is an abandoned practice because it was mostly attempting a "scientific" basis for prejudice.  It's been debunked as a predictor of anything useful, along with palm reading, horoscopes, handwriting analysis, etc.  There's always the danger that biometrics will be misapplied or abused for discriminatory purposed.  For instance, in the movie "Gattaca", DNA predictions were used to classify people into a caste system regardless of the merit or accuracy of the predictions.


What brings phrenology to mind is the recent popularity of head massagers such as "The Tingler" and the HeeBeeGeeBee(TM) vibrating head massager where a spider-like device of many wires massages the scalp reminiscent of the many probes used for measuring the skull shape.  Unless significant differences in skull shapes can be meaningfully observed then it's hardly a useful primary or even secondary identifier.


Forensic medicine may offer insights into useful biometrics since that explores legally admissible identification based on permanent and unique body characteristics such as dental records.


F.       Profiling vs. Intuition


Even if computers were given more input such as lie detectors (polygraph, voice stress analyzer), they lack human intuition.  Several terrorists were caught by immigration and boarder officers by observing that they were "twitchy" or overcompensating by "trying to act cool".


Sadly, humans have biases that sometimes interfere with proper judgement, such as racial profiling.


G.      But I tell you, my friend, it's not where you are, but your reason for being there. -- Utah Philips [Utah]


Citing [SCHN03]

Identification, authentication and authorization.  The three concepts are closely related, but in a security system it's critical that we tell them apart.

·         Identification: Who are you?

·         Authentication: Prove it.

·         Authorization: Here is what you are allowed to do


Most of this paper deals with the first 2 items: proving I'm me.  But mapping that to permissions is a different mechanism.  Visitor's passes are a form of consumable ticket: they expire based on time, or I hand it back on the way out.  Even a plain paper pass may be stamped "valid only for floor 9 on May 5th". Logging into computer grants me access to my files and shared facilities. It's considered trespassing to access facilities or information that are not part of that permission.


H.      You got to be very careful if you don't know where you're going, because you might not get there.  -- Yogi Berra


The Homeland Security Advisory System [HOMEL] is sadly a negative example of how to implement a security system.  Despite all the publicity for red/orange/amber alert, there are no clear procedures for people to follow or clearly stated goals or intentions.  "Vague alert" jokes are too true: the color code is mostly meaningless to people because there's no manual "what it means to me and what am I to do".  There is little confidence in the system determining the color-code because it's now "the boy who cried wolf".  Tremendous panic and anxiety has been caused by false alerts from unreliable sources.  The main tenant of asymmetric warfare is causing FUD (Fear, Uncertainty and Doubt) and economic damage at minimal cost. It seems the Homeland Security levels are helping the terrorists by giving a stamp of legitimacy by publicizing groundless threats from fakes.


I.         implementing faulty systems in a rush


I remember several unpleasant experiences where the person charged with implementing security was not solving the problem completely, or failed to heed others' experience.


The first problem was dictating policy to others instead of appealing to people's sense of duty or responsibility to participate.  People resent rules but tend to respond favorably if treated with respect.  It costs nothing to get people to collaborate.  Respectfully explaining the mutual effort required and motivating people to do their part ought to work wonders.  Sadly, I am yet to meet any such security expert.


One example: paper shredders appeared around the office without explanation.  I asked if I had missed a memo explaining their use for other sites had clear systems for classifying documents as "internal use only", "company confidential", "secret" and such, so I expected that only confidential or higher required shredding. That question nearly cost me my job, for I had embarrassed the security officer who had not gotten around to stating any policy for their use.


Another example: at one work site, there were security guards at the front entrance checking for ID cards, so none of the inner doors were locked.  Then ID card activated locks were added to the top floor doors.  Since the doors can be held open, people tended to “piggyback" and enter if a colleague had opened the door first.  There was no motivation to "key in" to an already open door, particularly since there was no need to "key out".  The system only logged people entering the top floor but not exiting. I tend to always key-in because on several occasions I used the security system's entry log to disprove false accusations that I was late to work or not on site for a particular day.  My diligence is due to the protection the system offers me from such accusations ("exempt" employees are not monitored by a timeclock system). If not for such personal motivation, it is unlikely I would always comply.


Manhattan offices have a simple solution to the entry problem: they use turnstiles so everyone must use their ID card to enter every time (but it's NOT needed to exit).


                                                                                                                                                         V.    Lessons learned


·         Correlate multiple factors, don't reply on just one technology or input.

·         Using only one technology or implementation leads to a monoculture where one attack will always succeed.

·         Security via obscurity only hides flaws.

·         Everybody in the system is responsible for their participation.  Only one weak link is needed for total failure.

·         No person, place or thing is above suspicion, so checks and balances are required at all levels.


                                                                                                                                                       VI.   Closing remarks

Security is an evolving field with new expectations and new technologies that may help solve them.  Since 9/11, there's an increased fervor for security, but until goals are clarified, there is no silver bullet.





Appendix A

RFID manufacturers and news



Alien Technology is a leading supplier of radio frequency identification (RFID) hardware that enables consumer packaged goods companies, retailers and other industries to improve their operating efficiency throughout their supply chains. ...



Matrics provides EPC compliant RFID systems for retail, CPG, defense, transportation and other vertical markets. ...



IDTechEx is the world's leading independent analyst on the development and application of RFID smart labels and smart packaging technologies.



a pleasant introduction to RFID




Wal-Mart puts big bucks into tracking tech

Last modified: November 7, 2003, 2:41 PM PST

By Alorie Gilbert Staff Writer, CNET


Wal-Mart plans to spend $3 billion over the next several years on a new inventory tracking technology that uses radio frequency signals to keep tabs on merchandise, sources familiar with the project said.


The system is based on a technology known as radio frequency identification (RFID), a new breed of computer network designed to track the location of everyday objects such as razors and shoes by embedding them with special microchips.  Wal-Mart has enlisted its top 100 merchandise suppliers to participate in the high-profile project, one of the first and largest of its kind in the retail industry.



Wal-Mart to throw its weight behind RFID

Last modified: June 5, 2003, 2:41 PM PDT

By Richard Shim Staff Writer, CNET


Inventory management technology that uses wireless signals to track products from the factory to store shelves is set to win a major new ally next week: Wal-Mart.


The retail giant is expected to throw its weight behind RFID (radio frequency identification) technology at the Retail Systems 2003 industry conference in Chicago on Tuesday. Sources familiar with the company's plans said executives will make a presentation encouraging its top 100 suppliers to start using wireless inventory tracking equipment--chips affixed to products, and scanners in warehouses--by 2005.



Supermarket cans RFID trials in Germany

March 01 2004 by Jo Best


Consumers not best pleased by tracking loyalty cards


The latest trial of RFID in high street shops at the German supermarket chain Metro has met with protests that have seen the retailer backtrack after consumers objected to the tracking tags turning up in their loyalty cards as well as consumer goods like Gillette razors.


Despite a promise by Metro that the stores will stop using RFID, civil liberties and privacy advocates protested outside the shop on Saturday.


An in-store kiosk was meant to disable the tags before shoppers left the supermarket, but it was found to be ineffective, meaning shoppers and their purchases could theoretically be tracked outside a store as well as inside.

Metro the fifth largest retailer in the world and the biggest in Germany - has also offered to replace the cards of any concerned shoppers with cards sporting bar codes instead.


Despite making no secret of its plans to the trade press, the Extra Future store in Rheinberg didn't reveal its plans to use the technology in 10,000 cards to its shoppers and the RFID tag was only discovered when one of the cards was taken apart by an activist.


While the store has decided to recall its loyalty cards, plans for an RFID-enabled inventory system across 250 stores and 100 suppliers will continue, said the retailer.


Metro isn't the first retailer to shelve plans for an RFID rollout after an unfavorable reaction from the public. American favorite Wal-Mart announced last year that it would be putting plans for RFID 'smart shelves' on ice, but like its German counterpart, would be using the tracking technology in the supply chain.



Wal-Mart cans 'smart-shelf' store trials

July 09 2003 by Alorie Gilbert and Richard Shim


Bar-code replacement smart tags will now only be used in its warehouses


Wal-Mart has unexpectedly cancelled testing for an experimental 'smart-shelf' in its US stores that would have used the controversial radio frequency identification (RFID) product tracking tags.


The trial with Gillette was due to begin at a store in Boston last month but Wal-Mart spokesman Tom Williams said this has now been ditched.


He said: "The shelf was never completely installed. We didn't want it.  Any materials that were there were removed. We never had products with chips in them."


RFID technology uses microchips to wirelessly transmit product serial numbers to a scanner without the need for human intervention and is seen as an eventual successor to bar-code inventory tracking systems, promising to cut distribution costs for manufacturers.


Wal-Mart's proposed smart-shelf system was designed to pick up data transmitted from microchips embedded in Gillette product packaging, alerting store managers via computer when stock is running low on the shelf or when items may have been stolen - two informative and powerful measurements in the retail business.


The trial would have been the most aggressive step yet by a retailer to push RFID from warehouses into stores. Backers of the technology eventually see billions of packaged goods tracked remotely using RFID sensors through in-store systems that might one day help prevent shoplifting and speed shoppers through automated checkout lines.


Those ambitious plans now are likely to take a backseat to proposals to upgrade warehouse operations with RFID technology, which will require fewer chips and less computational power.


Wal-Mart, the world's largest retail chain with 4,700 stores around the globe, said last month that it is urging its top 100 suppliers to attach RFID chips to cases and pallets of products that they ship to Wal-Mart warehouses.


A Gillette representative declined to comment on Wal Mart's decision to pull the plug on the wired shelf but said the company remains focused on helping UK supermarket chain Tesco and German retail conglomerate Metro with similar trials in Europe.


The smart-shelf trial by Wal-Mart was viewed as a potentially aggressive endorsement of an in-store application because of the company's ability to influence its suppliers and push the adoption of new technologies - something it helped to do with bar-code scanning technology in the 1980s. The unexpected cancellation of the test is letting some of the steam out of the market, but that may be a good thing, according to one analyst.


Jeff Woods, analyst with research firm Gartner, said: "The RFID industry has been floundering in a sea of science projects, which is what these trials have been to date. This is one of the most overhyped technologies out there, and this can be viewed as a precursor to the bubble bursting for RFID."


Privacy advocates have aired concerns about the technology and whether retailers and manufacturers would be able to monitor products after consumers purchased them.


But in May, several RFID chip manufacturers pledged to incorporate a "kill switch" that would be disabled at checkouts into their chips in a move to relieve consumer fears of the technology.


Economics may have played a role in Wal-Mart's decision to shelve its in-store RFID test. RFID chips are still too expensive for wide-scale use with consumer merchandise, according to Gillette spokesman Paul Fox.

While today's price of around 10 cents a chip is cheap enough to fuel initial trials the cost of the chips have to fall to a fraction of a penny if they are to become ubiquitous in stores, which could take up to 15 years, he said.


Alorie Gilbert and Richard Shim write for CNET


[several web sites report on RFID abuses and invasion of privacy]



The main web site for CASPIAN (Consumers Against Supermarket Privacy Invasion)


RFID chips, tiny tracking devices the size of a grain of dust, can be used to secretly identify you and the things you're carrying-- right through your clothes, wallet, backpack, or purse.




Business Week: "Industry is finally getting the message:

RFID is fine for pallets of goods in a warehouse, but not for people."



An x-ray of the card shows the internal antenna, and discusses the lecture about RFID privacy where the store knowingly lied and misled customers about the technology and the store's intentions.




RSA Security has developed a countermeasure to block scanning of radio-frequency ID tags, responding to privacy concerns about the tiny devices that would allow retailers and manufacturers to track the whereabouts of their goods within a store and beyond.


At a computer security conference in San Francisco,

RSA Security gave out medicine bottles filled with jellybeans.  Embedded in the bottle's label was an RFID tag similar to the kind that retailers may use to track their products. An RFID blocker tag, seen here embedded in a white mailing label pasted onto the back of a pharmacy bag, would jam frequencies sent out from the RFID tag on the bottle to protect the privacy of consumers.  The RFID blocker tag was pasted to the back of a pharmacy bag with a message from RSA Security explaining how the blocker tag they developed works to protect consumers' privacy.


The blocker tag, which can be placed over a regular RFID tag, prevents a receiver from scanning information transmitted by a tag by sending the receiver more data than it can read -- the equivalent of a denial-of-service attack. RSA doesn't have immediate plans to market the blocker and is waiting to see whether industry widely adopts RFID technology.

APPENDIX B: useful quotations

relating to security systems


You got to be very careful if you don't know where you're going, because you might not get there.

-- Yogi Berra


Woolsey-Swanson Rule:

People would rather live with a problem they cannot solve rather than accept a solution they cannot understand.


The forest is safe because a lion lives therein and the lion is safe because it lives in a forest. Likewise the friendship of persons rests on mutual help.

-- Laukikanyay.


Software entities are more complex for their size than perhaps any other human construct because no two parts are alike. If they are, we make the two similar parts into a subroutine -- open or closed.  In this respect, software systems differ profoundly from computers, buildings, or automobiles, where repeated elements abound.

-- Fred Brooks, Jr.


You see, I consider that a man's brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things, so that he has difficulty in laying his hands upon it.  Now the skilful workman is very careful indeed as to what he takes into his brain-attic. He will have nothing but the tools which may help him in doing his work, but of these he has a large assortment, and all in the most perfect order.

It is a mistake to think that that little room has elastic walls and can distend to any extent. Depend upon it there comes a time when for every addition of knowledge you forget something that you knew before.

It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones.

-- Sir Arthur Conan Doyle, "A Study in Scarlet"


If you are not for yourself, who will be for you?

If you are for yourself, then what are you?

If not now, when?


If science were explained to the average person in a way that is accessible and exciting, there would be no room for pseudoscience. But there is a kind of Gresham's Law by which in popular culture the bad science drives out the good. And for this I think we have to blame, first, the scientific community ourselves for not doing a better job of popularizing science, and second, the media, which are in this respect almost uniformly dreadful.  Every newspaper in America has a daily astrology column.

How many have even a weekly astronomy column?

And I believe it is also the fault of the educational system.  We do not teach how to think. This is a very serious failure that may even, in a world rigged with 60,000 nuclear weapons, compromise the human future.

- Carl Sagan, The Burden Of Skepticism, The Skeptical Inquirer, Vol. 12, Fall 87


I had a feeling once about mathematics -- that I saw it all.  Depth beyond depth was revealed to me -- the Byss and the Abyss.  I saw -- as one might see the transit of Venus or even the Lord Mayor's Show -- a quantity passing through infinity and changing its sign from plus to minus. I saw exactly why it happened and why tergiversation was inevitable -- but it was after dinner and I let it go.

 -- Winston Churchill


"I wonder", he said to himself, "what's in a book while it's closed.  Oh, I know it's full of letters printed on paper, but all the same, something must be happening, because as soon as I open it, there's a whole story with people I don't know yet and all kinds of adventures and battles."

-- Bastian B. Bux


It is not that polar co-ordinates are complicated, it is simply that cartesian co-ordinates are simpler than they have a right to be.

-- Kleppner & Kolenhow, "An Introduction to Mechanics"


Man is the best computer we can put aboard a spacecraft... and the only one that can be mass produced with unskilled labor.

Wernher von Braun (1912 - 1977)


Crash programs fail because they are based on the theory that, with nine women pregnant, you can get a baby a month.

Wernher Von Braun (1912 - 1977)


Of all men's miseries, the bitterest is this: to know so much and have control over nothing.

-- Herodotus




more about retina scanning


Retina scanning is hindered by cataracts and glaucoma.  Citing


... maps the capillary pattern of the retina, a thin (1/50th inch) nerve on the back of the as cataracts and glaucoma can render a person unable to use retina scan technology, as the blood vessels can be obscured.  IBG concerns have slowed the development of such technology, but investors apparently expect that to change:






By: Robert J. Harazin, CPP


This article appeared in the September 2002 issue of Security Technology & Design


"There is no single best biometric technology, but the requirements of a specific application determine which biometric system is best."


In today's world of increased security awareness and access control, everyone is looking for improvements in technology. There are three different authentication methods used in security today.


The first relies on something you know, like a password or PIN.  The second relies on something you have, like a card key, smart card or token. The last type of authentication relies on what you are-this type is biometric authentication. Biometrics is based on the measurement of physiological or behavioral characteristics to determine or verify identity.

Of these types, biometrics is the system that can afford the greatest degree of security.  Passwords and PINs can be guessed, lost or even shared, tokens can be stolen, but biometric data cannot. These systems provide other advantages over traditional card systems, including elimination of buddy punching timeclock and deterrence of fraud attempts.


Currently there are two primary uses for a biometric system: physical access and logical access. Physical access systems monitor, restrict or grant the rights to a user for movement into or out of an area.  When used in physical access systems, biometrics generally replaces or is used in conjunction with keys, access cards, PINs and security guards.  Logical access systems monitor, restrict or grant access to data or information.  Uses of logical access systems include logging onto a PC, accessing data from a network or authenticating a transaction. The basic biometric function of acquiring and comparing data is often identical between physical and logical access systems.


In our everyday lives, we are accustomed to recognizing friends' and co-workers' faces and voices. In a biometric system the actual matching function is much more complex.  The first thing a user must do to be able to use a biometric system is to present his or her biometric data. This step is called the enrollment process.  Biometric data is acquired and processed and then stored on what is called an enrollment template, which is kept in the system.


When a user presents his or her biometric data to the system for verification, another template is created, called a match template. The data on the match template is then compared to the data on the enrollment template.

A score is created for the comparison of the two templates, and this score is then compared against a threshold-a predefined number that establishes the score required for a match to occur.  The system will then grant access, refuse access or request another sample, depending upon the results of the comparison. There are several biometric technologies available today, each with its own strengths and weaknesses.  There is no single best biometric technology, but the requirements of a specific application determine which biometric system is best. The following graph shows some of the strengths and weaknesses of the leading biometric technologies available today.



Biometric Technologies | Ease of Use | Accuracy | User Acceptance | Required Security Level |

            Long-Term Stability | Error Incidence


Signature     | High   | High      | Medium | Medium    | Medium | Changing Signatures

Voice         | High   | High      | Medium | Medium    | Medium | Colds, Noise, Weather

Fingerprints  | High   | High      | Medium | High      | High   | Age, Dirt, Dryness

Hand Geometry | High   | High      | Medium | Medium    | Medium | Age, Hand, Injury

Retina        | Low    | Very High | Medium | High      | High   | Glasses

Iris          | Medium | Very High | Medium | Very High | High   | Poor Lighting

Face          | Medium | High      | Medium | Medium    | Medium | Age, Glasses, Hair



Signature Scan

The signature scan technology uses several aspects of an individual's signature to verify his or her identity. This technology measures the physical activity of the person signing and looks at the behavioral components of the signature, such as the stroke, speed and pressure of the individual's hand. Someone could learn to sign a person's signature so it is visibly identical to the real thing, but because this system operates using behavioral rather than physiological characteristics, it is difficult for an imposter to fool the signature scan system.


Voice Scan

Another biometric technology that is in use today is the voice scan system.  A user of this technology must speak a particular word or phrase to have his or her identity verified. Voice scans combine behavioral and physiological biometrics by using distinctive aspects of the voice-what is said and how it is spoken.  The voice scan system is text-dependent, meaning that a user must speak a particular phrase or word to be recognized. This system will not verify the voice of someone speaking random words or phrases that have not been entered into the system as a template. Most individuals will find this technology easy to use, but the error rate for identification could be high if the person has a cold or if environmental conditions around the reader distort or muffle the voice.


Fingerprint Scan

Fingerprint scan technology is the most commonly used biometric technology to identify or verify the identity of individuals. This type of system has made many technological advancements and is capable of a high degree of accuracy.  The acquisition of a high-quality image of the fingerprint is the first challenge

for a finger scan system. This is a major problem because fingerprint quality can vary from person to person and from finger to finger.  The fingerprint comprises ridges and valleys that form distinctive patterns, such as swirls, loops and arches.


Fingerprint ridges and valleys are characterized by discontinuities and irregularities known as minutiae. Minutiae are the distinctive features on which most fingerprint technology is based. An alternative technology is based on pattern matching.

Pattern matching verifies identity by examining a series of ridges as opposed to discrete points. The use of multiple ridges reduces the dependence on minutiae points, which are affected by wear and tear.


Finger scan technology is a strong solution for a range of environments.  It will likely continue to grow in use with logical and physical access applications, and will likely be central to the biometric industry's growth.


Hand Geometry Scan

Hand scan technology utilizes distinctive aspects of the height and width of the hand and fingers. This technology has been in use for many years and is mainly used for physical access and time and attendance applications.


To use this scan, an individual places his or her right hand on a metal surface with the fingers slightly separated and the palm resting flat.  Some units require the user to enter a PIN as well.  Hand scan devices are generally constructed out of metal and plastic and have few easily damaged components. These units are designed to be located in any type of environment, even where other biometric devices would be inoperable.  They will operate through temperature and moisture extremes, and will read even if the user is wearing thin latex gloves.  Because physical access devices are more likely to be exposed to the elements, this represents a major advantage for hand scan technology.


Retina Scan

Retina scan is perhaps the most accurate and reliable biometric technology.  It is also among the most difficult to use and is perceived as intrusive.  The retina is the surface on the back of the eye that processes light  entering through the pupil. Retina scan is usually used for access control where a high degree of security and accountability is required.


The operation of this device requires that the user place his or her eye very close to the unit's embedded lens.  Beneath the lens is the imaging component, which consists of a small green light against a white background.  The user watches this light, and, when triggered, the light moves in a circle, measuring the retinal patterns through the pupil. The user must remain perfectly still during this process, because any movement will compromise the image acquisition process.  The retina contains at least as much individual data as a fingerprint, and it is less susceptible to intentional and unintentional modification.  However, certain eye conditions and diseases such as cataracts and glaucoma can render a person unable to use retina scan technology, as the blood vessels can be obscured.


Two things detract from the retina scan's widespread use.  First, people feel that the eye is a delicate area, so many are hesitant to use the device.  Second, the cost per device puts it on the expensive end of the physical security spectrum.


Iris Scan

Traditionally used only in high-security access control applications, iris scan technology has now been introduced to the airline industry, prisons and the banking industry for use in ATMs. The iris scan process requires the acquisition of a high-resolution image of the eye by an infrared imager in order to effectively map the details of the iris.  Because the distinctive features of the iris differ substantially from user to user, testing has shown the iris scan to be extremely resistant to false matching.  Iris scan technology is a tremendously accurate biometric.


Face Scan

The human face has distinctive features that can be used to verify or identify individuals.  The features that are most often utilized are the upper ridges of the eye sockets, the areas around the cheekbones, sides of the mouth, shape of the nose and the position of major features relative to each other. These features are used because they are least likely to change over time. Facial scan systems can be used in conjunction with ID card systems, booking stations and for various types of surveillance operations. The most successful implementations of these systems take place in environments where cameras and imaging systems are already present.


The process begins with the image acquisition through a high-resolution camera.  Securing a quality image can be a problem if the subject is standing to far from the camera, the lighting changes or if the subject is at an angle to the camera.  A new and developing area for facial scan is in the area of surveillance.  Biometric surveillance systems are currently being used in major gambling casinos and in a few police applications. Of these two applications, casino usage is more widespread and less controversial. But in the public areas where law enforcement has tried to pick out possible criminals, the use of facial scan has proven to be very controversial because of the high number misidentifications. The major problem here is the enrollment factor.  Law enforcement for the most part is loading its systems with pictures of wanted criminals from mug shots or pictures of very low quality.  Another factor is that the wearing of hats, glasses, facial hair and hairstyles can affect the verification process. Facial scan technology in a closed environment with good enrollment procedures can afford good security and protection.


Some biometric devices are user friendly, while other types require a greater amount of training on the proper way for the user to present biometric information.  For example, placing your finger or hand on a reader is relatively simple, but the aligning of the head with a device for use with a retina, iris or facial scan can at times be difficult. As technology develops, the use of these devices will become easier and less intrusive.


Biometrics may offer increased security, increased convenience or enhanced services.  In some applications, the biometric system serves only as a deterrent, while in others it is central to the security system operation.  Regardless of the reason for using biometrics, there are two common elements that come into play with its use:

1.       The high degree of certainty regarding the verification of an individual's identity and

2.       The benefits that lead directly or indirectly to cost savings or to reduced risk of financial losses for an individual or institution.

Some biometric systems can be very costly, but sometimes price cannot outweigh the need for high security and protection.


This article appears permission by Cygnus Business Media, Inc


appendix D

RFID references:


RFID uses and abuses are often discussed in the comp.risks digest.



leads to Good RFID commentary




Microchips and Your Pet

What You Should Know Before Microchiping Your Pet



Recent Industry News




RFID Tags in New US Notes Explode When You Try to Microwave Them [I suspect it's just a metal thread]


We could have left it at that, but we have also paid attention to the European Union and the 'rfid' tracking devices placed in their money, and the blatant bragging of Walmart and many corporations of using 'rfid' electronics on every marketable item by the year 2005.



Euro bank notes to embed RFID chips by 2005

By Junko Yoshida

EE Times December 19, 2001

SAN MATEO, Calif. - The European Central Bank is working with technology partners on a hush-hush project to embed radio frequency identification tags into the very fibers of euro bank notes by 2005, EE Times has learned.  Intended to foil counterfeiters, the project is developing as Europe prepares for a massive changeover to the euro, and would create an instant mass market for RFID chips, which have long sought profitable application.



EPCglobal sets up RFID product code management system


more about SmartCard systems


Laptop computers are vulnerable to theft or casual tampering because most assume a single user.  Passwords and account locks are barely useful because the hard drive is so easily removeable (usually in an enclosure that facilitates removal), or external storage media are used (USB interfaced hard drives, CDs, floppies, solid state storage).


SmartCards or USB interfaced cryptographic devices are an effective solution because they encrypt the data on the disk drive as well as authenticate the user.


Most systems offer Key Escrow systems for recovering the disk data even if the SmartCard is lost or stolen.


The IBM Smart Card Security Kit claims:


The IBM Smart Card Security Kit is an integrated hardware and software SecureWay soluion. It provides advanced security features for desktop computers that includes Transparent Data Encryption, Multi-User access, Digital signature for both Netscape and Microsoft Internet Explorer and is also Security Dynamics "SoftID" ready.

·         Protects against information theft

·         Protects again unauthorized use of your computer

·         Provides file encryption and decryption

·         Easy transfer of self decrypting documents

·         Instant Secure Screensaver

·         Supports many widely used security applications


A.       Self Contained Credentials



RISKS-LIST: Risks-Forum Digest  Tuesday 4 May 2004  Volume 23 : Issue 35


ACM Committee on Computers and Public Policy, Peter G. Neumann, moderator


A recent edition of the Risks digest [risks_23_35] reviewed the book "Non-Repudiation in Electronic Commerce", Jianying Zhou, 2001, 1-58053-247-0


This relates to Jerry Chen's presentation of Non-repudiation Secure File Transfer where a method for secure, authenticated offline file transfer was presented.  Machine-readable id cards could benefit from that as well.


Most conversations start with exchanging identity and agreeing on how to proceed with the conversation (session key, encryption method, etc) and cannot proceed until each reply is received.


Analogously, most machine-readable ID systems require a real-time response from a central server to verify the id-number and verify if the person has permission for the action.


For example:

I swipe my magnetically encoded ID card at the front door.  The card reader sends to the central server "I am card #634592346"  The central server may reply

1.       "yes, unlock the door and let him in"

2.       "buzz and reject the card, it is no longer valid"

3.       "buzz and reject the card, it's the wrong time for him to enter"


The hand biometric reader may control a door too, and the protocol proceeds as follow:

1.       I enter my ID on the keypad, or swipe the ID card scanner to central server "employee 42 is at the door"

2.       server to scanner "let him prove it"

3.       I place my hand in the scanner and the readings are sent to the server

4.       the central server may reply

"yes, unlock the door and let him in because the hand matches the profile in the database"


All these systems fail if communication to the server is lost, or the server fails to respond.


Consider the way stores process credit cards.  Most use a terminal to a server that quickly validates if the card is valid and initiates a financial transaction.  But if the server is unavailable, the backup system it to look up the credit card number in a book of invalid numbers and take an imprint of the card to prove it was physically present.  This system fails to detect cards invalidated after the list was printed but it's mostly reliable and trusted.


Authentication can benefit from the techniques used for delayed transmission when a central server is not available.  Machine readable devices such as SmartCards or high density barcodes may contain their own certificates, or an entire message describing the bearer's credentials.  A server is needed only to assure none of the certificates were revoked and the card's not stolen.


It could work like this: NJIT generates a list of credentials for me (what buildings I may access, what facilities I may use, etc.) encrypts it and makes an electronic "envelope" for it.  I may store it on any medium (SmartCard, floppy, CD). When I want access to something participating in the security system, I present my credential. Just like the offline reading of the secure email, the credentials are unwrapped and validated.  A server is needed only for checking the revocation list.  If the server is not available, there is sufficient trust that the access may be granted.


I cannot alter or tamper with my credentials because I lack NJIT's private key so I cannot create a proper signature.

Appendix F

Subway fare systems


The NY subway system originally used metal coin-like tokens for the fare payment system.  Slugs (fake tokens) circumvented fare payment because it's easy to fool the mechanical-only turnstile mechanism.  Then the token design was changed to use 2 dissimilar metals, only to find that identical tokens were used in other states and they cost significantly less!


Now the all electronic "Metrocard" fare card system has totally replaced tokens.  But there's a new way to circumvent fare payment: bending the card gives free rides



Bending Your Metrocard


The Times looks at how Metrocards aren't safe from thieves trying to steal fares, specifically with techniques like "bending the card" which is a far cry from ancient techniques of stealing tokens.  The MTA estimates they lose $260,000 a year on card-benders, versus $5 million on turnstile jumpers. The Morning News coined a brilliant Metrocard phrase: Metrotard - A person in front of you at the subway turnstile who cant figure out how to swipe his or her subway pass.  Maybe they were simply fare swiping.  Oh, and the Times piece answers what's done with the discarded Metrocards that litter stations: Absolutely nothing.


Posted by Jen Chung in News: NYC


how to "bend" a metrocard

·         bend the back middle between the C and the A in the word CARD.

·         Bend right in the center in the black strip.

·         Swipe in the turnstiles 3 times. the forth time you should get through if done right.



How To Manipulate Metrocards


"Getting over" has been a time honored tradition in this city, passed down from one generation to the next. From booster bags to jamming payphones there always seems to be a way around everything.


My personal favorite was finding a way around turnstiles, or over them. A petty crime that allowed me, as a kid, to turn this city into a playground not to mention saving a couple of bucks. That changed when the city's crackdown on fare beating really cramped a lot of people's style.  But as I said, there always seems to be a way around everything. The following is a trick of the trade "How To" if you will, from the usual suspects. It might take a few tries to get it, so take your time and be on point. Once you get it, you'll thank me.  First of all you're going to need old Metrocards.  Only full fare cards can be used.  Every station is equipped with a machine that tells you the status of the card.


$) Now comes the tricky part. Bending the card correctly.  Along the bottom of the card it says "Insert this way/this side facing you."  The G spot is the backslash. Holding the card facing you with your index fingers on the back of the card, bend it slightly along the backslash.  Make sure that the crease doesn't go further than halfway up the black strip. This step is key, so be precise.


$$) Now for your first swipe. If the card was bent correctly, the screen on the turnstile should display, "please swipe again."  Do as it asks. After the second swipe the screen should display, "please swipe again at this turnstile."  If it doesn't, keep swiping until it does.

You can try unbending and re-bending the card to achieve the desired result.


$$$) Now, unbend your card and swipe a third time. This swipe should be the ticket.  The turnstile should been you through as if you had a buck fifty left on the card.  If it doesn't, swipe it a fourth time and that should do the trick.


DISCLAIMER: All this is, is the Metrocard system allowing you through in case you really do have a fucked up card.  It's not an exact science so don't be surprised if you have to try things a little differently than I've described them.  You only get one fare per card so it's not an end all be all for your transportation woes. This is illegal and should be treated accordingly.  I don't suggest attempting this in Times Square or at any busy station unless you're a pro.  Come to think of it, I don't suggest anyone doing this. Good luck.



Another new failure mode for the NY Subway System: Metrocard vending machine BSOD: Win NT.


The Chicago subway has a wireless fare card only for monthly passes. This sounds similar to the EZ Pass system: account status is available online and the account is linked to a credit card for auto-deduction.






How and where can I use my Chicago Card Plus?  To board a bus or enter through a rail station turnstile, simply touch your Chicago Card Plus to the touchpad on the front of rail station turnstiles and bus fareboxes on all CTA and Pace buses.  Chicago Card Plus is accepted for full fare payment on all CTA rail and bus routes, and Pace buses (except Pace route #835).  Metra does not accept CTA fare media.


Will my RTA Reduced Fare Permit SmartCard change to Chicago Card Plus?  No, this program will not affect your reduced fare SmartCard.  You will continue to use the same card.


What will the bus farebox and rail station turnstile displays read when I use my Chicago Card Plus?

Your choice of Pay-Per-Use or 30-Day Passes may not be accurately reflected on bus farebox and rail station turnstile displays but will be accurately reflected in your account. Your balance will never be displayed on turnstiles or fareboxes because your balance is held in an account and not on your card.


References on the CD



Jonas, Jeffrey

Balancing Privacy and Trust With A Smart Card Based National Identity Card

paper presented for NJIT's CIS786 Pervasive Computing

Summer 2003, unpublished.



Jonas, Jeffrey

Introduction to Smart Cards

paper presented for NJIT's CIS786 Pervasive Computing

Summer 2003, unpublished.



Jonas, Jeffrey

Introduction to WiFi

paper presented for NJIT's CIS786 Pervasive Computing

Summer 2003, unpublished.



Jonas, Jeffrey

Introduction to DMCA (Digital Millennium Copyright Act) and DRM (Digital Rights Management)

paper presented for NJIT's CIS786 Pervasive Computing

Summer 2003, unpublished.



Lutz, Robert  Augmented Reality, paper presented for NJIT's CIS786 Pervasive Computing

Summer 2003, unpublished.




ACM Committee on Computers and Public Policy, Peter G. Neumann, moderator

mirrored at




references NOT on the CD



Hiltz S.R., Han H., Briller V., 2003,

Public Attitudes towards a National Identity "Smart Card:"

Privacy and Security Concerns Proceedings of the Hawaii International Conference on System Sciences (HICSS), 2003.



Schneir, B.

Applied Cryptography Second Edition

New York: Wiley, 1996.



Schneir, B.

Beyond Fear: thinking sensibly about security in an uncertain world

New York: Copernicus Books, 2003.



Schneir, B.

Crypto-Gram is a free monthly e-mail newsletter on computer security and cryptography from Bruce Schneier



Requirements for IPsec Remote Access Scenarios



RFC 3193 - Securing L2TP using IPsec



RFC 1824 - The Exponential Security System TESS: An Identity-Based Cryptographic Protocol for Authenticated Key-Exchange (E.I.S.S.-Report 1995/4)



RFC 1875 - UNINETT PCA Policy Statements



U.S. General Services Administration Smart Card Initiative



Survey of Federal Smart Card Projects

February 2, 2004



Bruce Schneier.  Beyond Fear.  Copernicus Books, 2003



Crypto-Gram: a monthly newsletter on security





Understanding the Homeland Security Advisory System



other recommended reading

How SSL Works

Makes security products most notably they are the top level Certificate Authority

A major source of security software and devices such as SecurId tokens


To learn more about phrenology:

The Museum of Questionable Medical Devices in Minneapolis has one of the few remaining working models of a complicated mechanical phrenology device, the Psycograph, that made its big splash at the Chicago World's Fair in 1933. The hat-like device was placed on a person's head and provided a mechanical skull reading.


Museum of Questionable Medical Devices

Lists many other Phrenology web sites.