👉 Prisoner computing, also known as the Prisoner's Algorithm or the Precomputed Polynomial Evaluation (PPE) method, is a cryptographic technique that allows multiple parties to jointly compute a function over their private inputs without revealing those inputs to each other. Developed by mathematician Andrew S. Bernstein, it leverages the properties of polynomials and modular arithmetic to achieve this. In essence, each party generates a polynomial with their own input and shares the coefficients of this polynomial modulo a large prime number. The parties then combine their local polynomials using a precomputed product polynomial, which is derived from the inputs of all participants. This process ensures that each party's input remains private, as the final result is a polynomial whose coefficients are derived from the inputs without exposing them. The security of prisoner computing relies on the difficulty of evaluating such polynomials efficiently, even when the inputs are known only to a subset of the participants. This method has significant implications for secure multi-party computation, enabling collaborative data analysis and other applications while preserving privacy.
