Synchronized aggregate signatures
Jae Hyun Ahn, Matthew Green, Susan Hohenberger · 2010
An aggregate signature scheme is a digital signature scheme where anyone given n signatures on n messages from n users can aggregate all these signatures into a single short signature. Unfortunately, no "fully non-interactive" aggregate signature schemes are known outside of the random oracle heuristic; that is, signers must pass messages between themselves, sequentially or otherwise, to generate the signature. Interaction is too costly for some interesting applications.