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Comment by UltraSane

4 days ago

The NSA changed the S-boxes in DES and this made people suspicious they had planted a back door but then when differential cryptanalysis was discovered people realized that the NSA changes to S-boxes made them more secure against it.

That was 50 years ago. And since then we have an NSA employee co-authoring the paper which led to Heartbleed, the backdoor in Dual EC DRBG which has been successfully exploited by adversaries, and documentation from Snowden which confirms NSA compromise of standards setting committees.

  • > And since then we have an NSA employee co-authoring the paper which led to Heartbleed

    I'm confused as to what "the paper which led to Heartbleed" means. A paper proposing/describing the heartbeat extension? A paper proposing its implementation in OpenSSL? A paper describing the bug/exploit? Something else?

    And in addition to that, is there any connection between that author and the people who actually wrote the relevant (buggy) OpenSSL code? If the people who wrote the bug were entirely unrelated to the people authoring the paper then it's not clear to me why any blame should be placed on the paper authors.

    • > I'm confused

      The original paper which proposed the OpenSSL Heartbeat extension was written by two people, one worked for NSA and one was a student at the time who went on to work for BND, the "German NSA". The paper authors also wrote the extension.

      I know this because when it happened, I wanted to know who was responsible for making me patch all my servers, so I dug through the OpenSSL patch stream to find the authors.

      15 replies →

The NSA also wanted a 48 bit implementation which was sufficiently weak to brute force with their power. The industry and IBM initially wanted 64 bit. IBM compromised and gave us 56 bit.

Yes, NSA made DES stronger. After first making it weaker. IBM had wanted a 128-bit key, then they decided to knock that down to 64-bit (probably for reasons related to cost, this being the 70s), and NSA brought that down to 56-bit because hey! we need parity bits (we didn't).