4 ms·

You can't easily put backdoors in cryptographic algorithms that can be audited

• anonym29 3y ago
  ^ this post brought to you by RSA, ANSI, ISO, NIST, the NSA, and the authors of DUAL_EC_DRBG /s
  • gpderetta 3y ago
    ... Which iirc was immediately identified as suspicious during auditing.
    • a1369209993 3y ago
      And yet became a official standard anyway, and was occasionally actually used, despite the fact that is was obviously backdoored to anyone who knew anything about (elliptic-curve) cryptography. (It's literally a textbook-exercise leaky RNG, of the sort that you would find under "Exercise: create a elliptic-curve-based RNG that leaks seed bits within N bytes of random data." in a actual cryptography textbook.)
      • tptacek 3y ago
        You don't really need to understand elliptic curves to understand Dual EC. It's a public key RNG. The vulnerability is that there's a matching private key.
        • a1369209993 3y ago
          True, but my parenthetical was covering the opposite issue: it's possible to not realise DUAL_EC_DRBG is broken (rather than impossible to realise it) if your only knowledge of cryptography is, say, hash functions and stream ciphers (so you don't recognise public key cryptography from looking at it). It's unlikely, because DUAL_EC_DRBG is really obviously broken, but I wouldn't fault someone who knew nothing about elliptic-curve cryptography for missing it, even if they were familiar with other types of cryptography. (I would fault them for claiming that it's secure, rather than recognizing that they don't know enough to evaluate its security, but you can't conclude something's backdoored just from that.)
    • anonym29 3y ago
      The assertion I was refuting was that they couldn't be easily inserted into an audited library, not that they wouldn't be detected.
• tptacek 3y ago
  You certainly can.