2009-06-02

One-time key

"Never store your PIN number near your credit card" says your credit card company. AL has a better idea. When he gets a CC, he writes down in a think black permanent marker, right on the credit card.. the XOR of this PIN and other number which he never tells anybody.

This way, he can always recover the PIN if it is forgotten, and whoever steals the card will immediately be locked as he will try to enter the XOR.

All this is great, of course, and at last there's a service to help you. You just enter your life's master password, and neither it nor the generated per-website passwords will ever be sent to their server.

1 comment:

Winterrain said...

yeah but:

1] how do you log into windows?, what if you use multiple machines.

2] what if someone finds out your master password?

:/