Coinflip

Coinflip is a highly secure client/server program and protocol that generates random bits for two people securely over the internet. It ensures that the two parties do not have to trust each other to convince each other that the bit is genuinely random. The program derives its name from the real-life concept of flipping a coin, which is equivalent to generating a random bit on a computer - it's either a 1 or a 0.

Coinflip is based on a slightly modified version of "Coin Flipping Using One-Way Functions" protocol, a highly secure method outlined in Bruce Schneier's Applied Cryptography 2nd edition. However, there is one weakness in the protocol, Alice acting as a server in a coinflip procedure repeatedly sends the same value to Bob resulting in the breach of security. Recent papers highlight the vulnerability of one-way hash functions - if there is enough money and time, collisions can be precalculated.

However, Coinflip offers a solution to this problem by having both parties choose part of the random data, and using whatever size random number preferred. This nullifies Alice's collision attack since Bob is expecting to see x contain his random data whereas Alice can add her data to make Bob's array attack infeasible.

In conclusion, Coinflip is highly recommended for anyone seeking a seamless and trustworthy method of generating random bits for secure communication over the internet while acknowledging the possibility of hash function collisions.