Extraction Security of Sequential Aggregate Signatures

Aggregate signature schemes enable anyone to compress many signatures into one. Besides the unforgeability of aggregate signature, another property called extraction sometimes is useful. In sequential schemes, computed incrementally by signers. We introduce security in context which can be seen as an analogy introduced Boneh et al. CRYPTO 2003. addition practical meaning, it also has benefits construction hierarchical identity-based we will point out. study several well known and prove some them satisfy security.