A Tightly Secure DDH-based Multisignature with Public-Key Aggregation

From the birth of blockchain technology, multisignatures attract much attention as a tool for handling transactions. Concerning application to blockchain, with public-key aggregation, which can compress public keys signers single key, is preferable standard multisignature because and signature used in transaction are stored verify later. Several schemes key aggregation proposed, however, there no known having tight security reduction. We propose first whose proven be tightly secure under DDH assumption random oracle model. Our based on DDH-based by Le, Yang, Ghorbani, our proof different from theirs. The idea originates another Bonnecaze, Gabillon one. By tailoring their setting admits we prove multisignature.