Here's a better overview of password authentication: http://www.matasano.com/log/958/enough-with-the-rainbow-tables-what-you-need-to-know-about-secure-password-

Here's a better overview of password authentication: http://www.matasano.com/log/958/enough-with-the-rainbow-tables-what-you-need-to-know-about-secure-password-schemes/ http://www.matasano.com/log/958/enough-with-the-rainbow-tabl... It explains why using fast hash algorithms such as MD5 or SHA1 is a bad idea for the purpose of password authentication.