[EthanHeilman]

Yes and no better example than DES in which the NSA hardened DES against differential cryptanalysis and then reduced the key size from 128 bits to 54 bits so they could break it. Given the prior actions of the NSA is doesn't seem unbelievable that they would both harden and backdoor linux.

[twoodfin]

Who was arguing for 128-bit DES? Wikipedia says IBM wanted 64.

[EthanHeilman]

The original version of DES was called Lucifer and used a 128 bit key. http://en.wikipedia.org/wiki/Lucifer_(cipher)

The NSA choose the key size of DES since they were running the process (making DES 256 times weaker than a 64 bit key).