One of the more interesting papers I've read (which you/they don't have) is 'A simple algebraic representation of Rijndael.' [1] The paper contains equations which if solved would reveal a major weakness in Rijndael/AES, the current standard for actual TOP SECRET Classified information. [2]

[1] http://taz.newffr.com/TAZ/Cryptologie/hash-lib-algo/aes/rdal...

[2] http://en.wikipedia.org/wiki/Advanced_Encryption_Standard#Se...