S/key

A security system from Bellcore that eliminates sending the same password over the network each timethe user logs on.
A series of password are generated at one time, and each password is used only once. The host system stores only the last password;
for example, if 99 passwords are generated, it holds password 99 along with the userid and random number used to seed the hashing process that created them.
In the next session, the user would log on with password 98, then 97 and son on.

S/key
Phím bảo mật S.