For Bitcoin it is common knowledge that 6 confirmations suffices. For the hundred of Alt Coins however, I'm not sure what the best practise to be protected enough from double-spents and the likes is.

I saw Bter.com requires different confirmations varying on which Altcoin you want to deposit.

For example COMM-coin requires 10 confirmations, but BBQ coin 6, and Infinitecoin only 4.

Is there a mathematical method behind this? How do they know how many confirmations to require?

  • Isn't it related to the (expected) block time? That would sound a bit logical. For example, bitcoin takes around 15-20 minutes for each block. Not sure though, interesting question!
    – Mathias711
    May 21, 2014 at 19:34

1 Answer 1


Yes, there is a mathematical grounding behind this, namely Poisson distribution. See Satoshi's original paper (last pages) for some details about calculating the odds of a successful double spend attack given a certain portion of the networks computation capacity. This also means of course that networks with a larger hashing power are more susceptible to an attack than networks with lower hashing power.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.