Time-Lock Puzzle
Definition
A time-lock puzzle is a cryptographic primitive that encrypts data so it can only be decrypted after a specific amount of computation time. Unlike simple delays, the computation cannot be parallelized—guaranteeing a minimum time must pass regardless of computing resources.
Technical Explanation
Time-lock puzzles typically use repeated squaring in modular arithmetic: computing x^(2^T) mod N for large T requires T sequential squarings that cannot be parallelized without knowing the factorization of N. The puzzle setter knows the shortcut; solvers must compute step-by-step.
Applications include: delayed data revelation, fair multiparty computation, sealed-bid auctions, and dead man's switches. The puzzle guarantees minimum delay even against adversaries with massive parallel computing resources.
SynX Relevance
Time-lock puzzles complement blockchain timing guarantees. While blocks provide discrete time steps, time-lock puzzles offer continuous time delays—useful for complex protocols requiring guaranteed future revelation without trusted third parties.
Frequently Asked Questions
- Can quantum computers break time-lock puzzles?
- Standard constructions may be vulnerable. Quantum-resistant time-locks are an active research area.
- How accurate is the time delay?
- Depends on puzzle parameters and solver hardware—approximate but guaranteed minimum.
- What's the difference from timelock transactions?
- Blockchain timelocks use block height; time-lock puzzles use computation time.
Time-bound cryptographic guarantees. Explore SynX