Another Fair BitCoin Toss

Using Blum’s Protocol

Previously, we implemented a fair coin toss on Bitcoin using XOR. We introduce an alternative way of implementing it using Blum’s original coin tossing protocol¹.

Coin Toss

It consists of the following steps:

  1. Alice chooses prime numbers p and q. He tells Bob N = p * q. Alice chooses p and q to be extremely large so that Bob cannot feasibly find them from N.
Coin Toss Contract

[1] Coin Flipping by Telephone: A Protocol for Solving Impossible Problems. Blum (CRYPTO 1981).

[2] x and N have to be coprime to ensure 4 square roots.

sCrypt Inc (https://scrypt.io) is a company with mission to providing integrated on-chain smart contracting solutions on Bitcoin SV. scrypt@moneybutton.com

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