Problems with authentication

Columnist Paul A. Strassmann discusses the challenges involved with various methods of authentication.

Purloining a person's electronic authenticity is the most insidious way for invading individual privacy. If you...

can masquerade as another person, there are no limits on how much you can compromise the privacy and integrity of anyone's online data. For this reason, I will concentrate today on the adequacy of personal authentication methods.

Last month, a close relative -- a computer consultant -- died suddenly. Just about all of his affairs, including financial records, were on his laptop, without backups. When I finally got hold of the laptop, it was relatively easy to retrieve his records. I did not bother trying to crack his password with one of the hacker programs readily available (see All I had to do was install another version of a Microsoft operating system and pretend I was the deceased relative. The e-mails and financial records became instantly available!

This story illustrates what is perhaps most often missed when experts discuss privacy matters. Nowadays, protecting data transmissions as well as safeguarding data files attracts disproportionate attention. As I see it, the major threats originate from perpetrators masquerading as persons who already have the necessary access privileges. The bogus personalities can be just about anyone, but most often they are insiders, such as maintenance programmers, consultants or equipment repairmen.

Perhaps the single most important requirement for safeguarding personal privacy in a networked world is to positively and reliably assure the authentication of an individual who is requesting valuable network services. All privacy safeguards are easily swept away if a hostile intrusion can be launched to appear as coming from a trusted source. For this reason, I will devote this article to reviewing the problems with the existing approaches to authentication. I will also suggest how one ought to deal with questions of trustworthiness.

The problems with passwords

Passwords are by far the most used and most easily subverted method of personal authentication. If an organization institutes policies to ensure secure passwords (such as frequently changed alphanumeric upper/lower case combination of at least 10 characters) the inconvenience is so great that such a policy will be violated in an overwhelming number of cases. I know that such is the case from inspections of data centers containing classified data.

If security personnel do enforce a policy of elaborate passwords, the employees will write down the incomprehensible codes for easy access -- usually in places where such paper records are easily compromised. If an organization does not impose tight rules for the management of passwords, easily memorable words (and therefore easily cracked) will be preferred. Such practice tends to encourage re-use of easily memorized words for repeated uses. As an example, I find that just about every online business will always ask me to set up unique personal authentication as well as a new password. As a matter of principle, I never use the identical password twice. Consequently, I have accumulated over the past two years 292 unique active passwords! For instance, I have passwords for Adobe, Active Share, Amazon retail, Amazon publisher, American Airlines, American TownNetwork, Amtrak, Apple, Army (four sets), AT&T, Auction Watch and AuthorizeNet. This accounts just for all my "A"s! If I would not follow the policy of assigning unique passwords every time I am asked to set up one, I would increase my risks because any intrusion attempt into my records would commence with picking up a password from a known and less protected site, assuming that I use the same name for all.

To get around the problem of too simple passwords or of identical passwords for access to diverse sites, we now have a single sign-on solution from Microsoft (Passport). Accordingly, a single access code will unlock a central password "vault" that will then automate authentication processes. Though the concept of a single access master password solves many of the problems noted above, it saddles the authentication process with the risk that if access to the Microsoft operated "vault" is compromised, all privacy becomes compromised.

The problems with smartcards

Every time a person uses a smartcard, the implicit assumption is that the computer has not been compromised. The possibility always exists that the computer (or any other device implanted on the Net along the way) has been infected by a hidden software routine that exploits the user's identity after authentication has been accomplished. Because users authenticate themselves to a potentially compromised computer, they can never be secure in their subsequent computer transactions.

Perhaps the greatest inhibition to the use of smartcards in electronic commerce is their variety. The chances of adoption of smartcards as the universal means for authentication of individuals in electronic commerce are nil. Access security requirements vary depending on the severity of risks and local circumstances. Therefore, a wide range of smartcard solutions is almost certain to persist. Technology obsolescence and proliferation will continue to inhibit the adoption of smartcards and reduce the applicability of this means for solving personal privacy issues.

The problems with biometrics

Certainly a fingerprint or iris scan can identify an individual. Unfortunately, the means for acquiring biometric records are neither convenient nor inexpensive. Even then, biometrical records will not result in a completely secure system. Obtaining a copy of an individual's biometrics can be trivial. I have seen two movies where a waitress lifted a fingerprint from a glass in a restaurant for nefarious uses. There are also devices that can capture iris images of a person walking within a few feet of a video camera (often behind a one-way mirror) so that it can be duplicated and used for illegitimate purposes. The real problem with biometrics is that once an individual's biometrics has been compromised, they are compromised for life and can never be trusted again. However, my most severe objection to biometrics as an authentication method is their reliance on a central database that contains the identifying graphic templates. If such database is compromised, then the biometrics of ALL users in the database are compromised for life.

Voice recognition must be also considered as a potential authentication biometric. Unfortunately, the technology is as yet not sufficiently reliable, is expensive and difficult to implement. It also suffers from all of the disadvantages of having to rely on a central database for storing voiceprint templates.

The solution to personal authentication

We are witnessing a rapid shift from desktop computing to mobile computing wherein the functions of cell phones are integrated with the functionality of personal data appliances (PDAs). I happen to own such a device (the Kyocera Smartphone with full Palm PDA features, running on Sprint Network). In effect, the cell phone/PDA device makes available an authentication means that combines the best of password vaults, smartcards and biometrics, while avoiding most of their disadvantages. How can that be done?

The solution is to utilize the cell phone/PDA to combine all of the available authentication methods into a single device and thus rely on the combinatorial powers of three (or four) separate and distinct security methods to deliver verified authentication of a person. In other words, my cell phone/PDA becomes the smartest of the smartcards one can conceive because its contents are entirely under the owner's physical control. It is not under control of a centrally administered database that can be compromised. The only way to corrupt the uses of the cell phone/PDA phone is to steal it, but even then it would be of no use to anyone since unlocking its utility, as a smartcard, requires additional steps.

Here is how the additional steps work (it works on my Kyocera): Step #1: When I turn the device on, it asks me for a password to access to the highly encrypted password vault stored in the flash memory. That opens the PDA, which is now capable of acting as if it were my smartcard. Step #2: The PDA then asks me for my signature or a pre-defined handwritten phrase. The idiosyncrasies of my writing style have been already captured in an encrypted template. If my writing and the template match, I have positively identified myself and I am ready to conduct business. Step #3: Under certain circumstances, additional security can be obtained by voice recognition. Since the device in my hand is already a cell phone, this supplemental means for authentication can be advantageous, especially when dealing with lower security needs.


Concerns about the preservation of personal privacy in electronic commerce involve a wide range of security measures. I have concluded that obtaining assured authentication of a person's identity is by far the most critical inhibitor to future progress to expand electronic commerce on an all-pervasive global scale. With the rapid availability of increasingly powerful cell phone/PDA devices, time has come to abandon the current approach of viewing passwords, smartcards and biometrics as isolated solutions for securing assured authentications. Combining multiple authentication techniques in a personally owned and individually calibrated physical device seems to hold the promise of protecting individuals against purloined access codes to their private data.

About the author:
Paul A. Strassmann is the former Director of Defense Information, U.S. Department of Defense. He serves on the Board of Directors of TrioSecurity of Colorado Springs, Colo., a firm pursuing the development of innovative network authentication technologies.

This was last published in April 2002

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