Probabilistic payments are outputs that allow a pseudorandom function to decide which of n parties will be able to spend the funds.

For example, Alice and Bob each deposit 1 BTC into a contract that pays one of them the full amount based on the result of a cryptographically fair coin flip.

A particular focus of attention for probabilistic payments in Bitcoin is for trustless micropayments. For example, Alice wants to pay Bob 1 sat, but that would be uneconomical because it will cost several hundred sats for Alice to create the payment and for Bob to later spend it. Instead, Alice offers Bob 10,000 sats with a 0.01% probability. On average, that’s equivalent to him receiving 1 sat.

Probabilistic micropayments have been proposed as an alternative for trimmed HTLCs.

Primary code and documentation

Optech newsletter and website mentions

2025

Previous Topic:
Pooled mining

Next Topic:
Proof of payment

Edit page
Report Issue