4 ms·

Does it have advice for selecting an IV?

• cperciva 13y ago
  CTR mode doesn't have IVs. It has a counter: Start at zero and count upwards.
  • X-Istence 13y ago
    Depending on if the key may be reused having a non-zero nonce may be a good idea too... --- And I just realised who I am replying too, off course you know this.
    • cperciva 13y ago
      I was being a bit facetious in discriminating between "IV" and "nonce"... they're almost two sides of the same coin.
  • StavrosK 13y ago
    And don't overflow.
    • cperciva 13y ago
      If you need to send more than 2^68 bytes of data, you've got bigger problems than your crypto breaking.
      • StavrosK 13y ago
        You're assuming a correct implementation with a 64-bit counter, though.
        • cperciva 13y ago
          Yes. I'm also assuming people have correct implementations of AES.
          • tptacek 13y ago
            I have never exploited an incorrect implementation of an AES core in a real application, but have exploited "broken" counters.