4 ms·

Why double sha256?

• vscode-rest 7mo ago
  a that’s the botcoin hashing algorithm.
  • oblio 7mo ago
    I figured that part out, I wonder why it's being doubled.
    • vscode-rest 7mo ago
      That was the way satoshi wanted it. No other explanation is known.
• haakon 7mo ago
  The disappointing truth is that we simply don't know. Satoshi never explained it. For SHA-2 it can be used as a mitigation against length-extension attacks¹, and this seems like the most likely explanation, but it's just speculation. ¹ https://en.wikipedia.org/wiki/Length_extension_attack https://en.wikipedia.org/wiki/Length_extension_attack
  • vscode-rest 7mo ago
    Would length extension impact bitcoin? The messages aren’t secret afaik.