Biham E., Biryukov A., Dunkelman O., Richardson E., Shamir A. Initial Observations on Skipjack: Cryptanalysis of Skipjack-3XOR.//http://www.cs.technion.ac.il - Technion - 1998.
Blaze M., Diffie W., Rivest R.L., Schneier B., Shimomura T., Thompson E., Wiener M. Minimal Key Lengths for Symmetric Ciphers to Provide Adequate Commercial Security.//http://www.schneier.com - January 1996.
Шнайер B.Prikladnaja cryptography. Reports, algorithms, initial texts in language of Si. - the Lane with English: М: Publishing house TRIUMPH, 2002 - 816 with.
Partyka T.L., I.I.information's Priests safety. The manual for students of establishments of average vocational training. - М: the FORUM: INFRA TH, 2004.