4 ms·
Though when the NSA has done things like this in the past, we've found their choices prevented implementation weaknesses that weren't found (by anyone else) for
by rthomas6 10y ago
Though when the NSA has done things like this in the past, we've found their choices prevented implementation weaknesses that weren't found (by anyone else) for several more years.
- Bartweiss 10y agoCan you follow up on that? I've never heard that story and I'm really curious. On the narrower point, though, it's been shown that Dual_EC_DRBG is broken, and that the NSA values compromised the implementation instead of strengthening it.
- hatsunearu 10y agoS boxes in DES were originally nonexistent/vulnerable to differential cryptanalysis when IBM first made Lucifer.
- jschwartzi 10y agoWhen has this happened? I'm curious about things that could cast the NSA in a positive light.
- danielvf 10y agoThe DES standard's S-Boxes were changed by the NSA in the 1970s. It was long thought that this was to weaken them. However in the 1990's differential cryptanalysis was publicly discovered, and the NSA's changes to the S-boxes were found to have hardend DES agaist differential cryptanalysis.
- PeCaN 10y agoNow here's something fascinating. According to https://en.wikipedia.org/wiki/Differential_cryptanalysis#History¹ https://en.wikipedia.org/wiki/Differential_cryptanalysis#His..., IBM discovered differential cryptanalysis in the 1970s when designing DES. They opted to keep it a secret, given its general applicability against ciphers. It is unclear whether IBM shared it with the NSA or the NSA discovered it independently, but there's strong evidence that both IBM and the NSA were aware of differential cryptanalysis well before the public discovery in the 90s. ¹ This has what looks like a good citation but requires a subscription to access the relevant paper (sigh).