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Hackers Beware
book

Hackers Beware

by Eric Cole
August 2001
Beginner to intermediate
800 pages
22h 39m
English
Sams
Content preview from Hackers Beware

How Does UNIX Encrypt Passwords?

UNIX uses an encryption algorithm called Crypt to encrypt its passwords. Crypt is a hash algorithm, which performs a one-way transformation of the password. There is no way to unencrypt a password that has been encrypted with Crypt. To guess a password, an attacker runs a password guess through Crypt and compares the encrypted guess with the encrypted password; if there is a match, the password has been guessed.

Each encrypted password is 11 characters and is combined with a 2-character salt to get a 13-character password. A salt is a random string that is used to randomize the password. Without a salt, two users who have the same password would have the same encrypted password. With a salt, each user has a different ...

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Publisher Resources

ISBN: 0735710090Purchase book