Saturday, October 30, 2010

Choosing the right authentication method

There’s lots of talk about whether smartcards are better than one-time passwords (OTP), or is OTP easier than smartcards to implement, or is a soft-token as secure as a hard-token? I came across this article
“Proof Of Identity: How To Choose Multifactor Authentication” which had a pretty good run down on the various options, how secure each option was and how easy or hard it was to maintain those authentication methods. The article is below but there’s also a link to a white paper on the topic (requires registration) which you might find useful to read. As you can imagine, the answer to the question of which authentication method is best is “it depends”. Let me tell you how I would choose:

Ask yourself this question: Do you trust your employees? Do you run new hires through employment verification? If the answer is a basic yes then in my opinion you don’t need fancy (e.g., iris scans) or real heavy-duty strong authentication. You can get by with SMS tokens or OTP-based soft-tokens that run on your smartphone. If the answer is no, then you are more likely a government department or your firm is somehow working in a sensitive area (defense, government-related, power plant, etc.) and you are not allowed to trust your employees. In that case, go for the gusto, use a smartcard or fancy biometrics.
To control access to your Web-based applications, you need to identify and authenticate anyone wishing to use them -- that is, verify they are who they say they are. But how do you choose the right method of authentication? There's the rub.
Why do you need to implement strong or two-factor authentication for your Web applications? First, lawmakers have pushed security to the top of the agenda, and strong authentication is part of that agenda. Laws such as Sarbanes-Oxley and requirements such as PCI DSS mean single-factor authentication is no longer adequate for protecting access to high-value or personally identifiable information and providing reliable audit trails.
Second, any organization that sees customer trust as a business priority needs to provide secure authentication, and the password approach doesn't do that. Many organizations, though, are wary of implementing strong authentication due to its perceived cost. However, managing passwords can be expensive, too. They provide too low a level of trust to be considered a viable option where assets of any value are involved.
And the situation's getting worse. The growing use of number-crunching power of modern graphics cards to carry out brute-force attacks will soon make it trivial for hackers to crack strong passwords. Adding a second-factor credential to the authentication process provides additional security as well as a higher level of trust between a user and an application. Let's look at some of the options for authenticating users to Web applications.
The technologies for implementing strong Web authentication are:
  • Soft or hard digital certificates
  • One-time passwords (OTP)
  • Challenge-response
  • Authentication-as-a-service (AaaS)
Management is going to want a solution that's effective, flexible, and scalable, and can be implemented with minimum disruption and cost. Your customers, on the other hand, will want a solution that not only offers increased security but is easy to use.
There are three key factors to consider when choosing the right solution: time, risk and cost. If you know what your users will bear in terms of time to log on, and if you can weigh the risks associated with each method against its costs, you will find the solution that fits best for your applications.
For a detailed discussion of how to evaluate these factors and how they stack up against the various alternatives in Web authentication, download the full report.

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