Microsoft Abandoning Passwords For A Different Obsolete Security Mechanism?
from the unintended-consequences... dept
Just a day after Microsoft admitted they’re going to ditch passwords alone for two-factor authentication in the upcoming Longhorn operating system, Bruce Schneier is explaining why two-factor authentication is no longer secure. He’s speaking specifically about banks using two-factor authentication (generally your username/password plus a token that is generating a new random number every minute), but it certainly applies to the Microsoft announcement as well. Basically, the argument is that two-factor authentication doesn’t protect against active attacks, like man-in-the-middle or trojans — both of which piggyback on the user successfully logging in with the two factor authentication. While it does prevent some of the more basic fraud, the prediction is just that scammers will move up the scale, and start focusing more on these kinds of active attacks. Of course, it does still prevent scammers from logging in on their own. They can only piggyback off an existing connection. However, it is a good reminder that scammers are always going to figure out some way around whatever technology becomes common for security.
Comments on “Microsoft Abandoning Passwords For A Different Obsolete Security Mechanism?”
PKI and 2 factor authentication
The article seems to mention only one method of using hardware tokens for two factor authentication. If used with a public key infrastructure (PKI) with a certification authority (CA), 2 factor authentication is very secure. This is because all data is sent with public/private key encryption and private key data signing, which prevents man in the middle attacks and trojan attacks. These attacks are prevented because the encryption ensures data cannot be intercepted and interpretted, and the signing enures who sent the data and that the data has not been changed. The private key for the user is stored on the hardware token, ensuring the security of the key. Longhorn (as well as the 2 factor authentication already available on windows networks) will use PKI for logging in, as do most SSL servers.
no (practical) safeguard will prevent every attack
That’s Schneier’s message and it’s well taken. But that doesn’t mean universal adoption of two-factor authentication isn’t a good idea. Hardware has advanced to the point where eight-byte passwords are practically useless.