CWI Cryptology Group

Abstract: In this talk, I will describe hinTS --- a new threshold signature scheme built on top of the widely used BLS signatures. This scheme achieves the following desirable features:
- A silent setup process where the joint public key of the parties is computed as a deterministic function of their locally computed public keys.
- Support for dynamic choice of thresholds and signers, after the silent setup, without further interaction.
- Support for general access policies and native support for weighted thresholds with zero additional overhead over standard threshold setting.
- Strong security guarantees, including proactive security and forward security.
This scheme is practical with aggregation time for 1000 signers under 0.5 seconds, while both signing and verification are constant time algorithms, taking 1 ms and 17.5 ms, respectively. (Based on joint work with Abhishek Jain, Pratyay Mukherjee, Rohit Sinha, Mingyuan Wang, and Yinuo Zhang)