Time-Lock Encryption: Practical Applications and Algorithms

This lecture presents a comprehensive overview of time-lock encryption (TLE), focusing on a practical implementation known as threshold time-lock encryption (tTLE). The instructor begins by explaining the concept of TLE, which ensures that information remains encrypted until a specified time has elapsed. Two primary approaches to TLE are discussed: puzzle-based and trusted agent-based methods. The lecture highlights the evolution of TLE schemes, including significant advancements made since its introduction. The instructor then delves into the technical aspects of tTLE, detailing the algorithms involved in encryption and decryption processes. The use of threshold BLS signatures for decentralized key release is emphasized, showcasing how this enhances security and trust. Practical applications of TLE are explored, such as in sealed bids and exam results, where information must remain confidential until a designated time. The lecture concludes with a discussion on the robustness and security properties of tTLE, as well as potential future work in the field, including improvements and adaptations for quantum resistance.