Emulating OP_RAND in Bitcoin

TL;DR

This paper introduces a trustless, protocol-agnostic method to emulate the OP_RAND opcode in Bitcoin using an interactive game, enhancing privacy and security without protocol modifications.

Contribution

It presents a novel approach to emulate OP_RAND through a trustless game, enabling probabilistic outcomes without requiring Bitcoin protocol updates or specific scripts.

Findings

The protocol is unrecognizable to external parties.

It does not require Bitcoin protocol updates.

The approach is demonstrated on the Thimbles Game.

Abstract

This paper proposes a method of emulation of \verb|OP_RAND| opcode on Bitcoin through a trustless interactive game between transaction counterparties. The game result is probabilistic and doesn't allow any party to cheat, increasing their chance of winning on any protocol step. The protocol can be organized in a way unrecognizable to any external party and doesn't require some specific scripts or Bitcoin protocol updates. We will show how the protocol works on the simple \textbf{Thimbles Game} and provide some initial thoughts about approaches and applications that can use the mentioned approach.