3 ms·

As long as neither party has any way to manipulate the hash. Should probably add a 0th step where the payer commits to use a specific signature.

• kobeya 9y ago
  The signature doesn't matter. Allowing the payer to change it only increases (potentially) the odds of them having to pay, which they won't do. In some constructions--in others it has no effect.
  • infogulch 9y ago
    Ok it looks better after looking at it again. Thanks.