According to Mark Eichin:
The only "backdoor" concept I've heard which had a technical basis behind it was a few years back, when some researcher figured out a way to *produce* S-boxes with particular types of holes, and concluded that it was impossible to identify if the holes where there or not unless you knew the precise formulation... I think it even had a two-of-three challenge, ie, published 3 sets of s-boxes, one or two of which were "trapped" in this way, as a challenge for people to find methods of locating them. (The technical basis stops there -- the psychological or political question that follows is "did NSA/IBM know about this technique? Assuming they did, did they choose the s-boxes with or without holes?")
Could someone tell me what an s-box is? Thanx in advance. +-----------------------+-----------------------------+---------+ | J. Michael Diehl ;-) | I thought I was wrong once. | PGP KEY | | mdiehl@triton.unm.edu | But, I was mistaken. |available| | mike.diehl@fido.org | | Ask Me! | | (505) 299-2282 +-----------------------------+---------+ | | +------"I'm just looking for the opportunity to be -------------+ | Politically Incorrect!" <Me> | +-----If codes are outlawed, only criminals wil have codes.-----+ +----Is Big Brother in your phone? If you don't know, ask me---+