Cryptanalysis of a Certificateless Aggregate Signature Scheme

Certificateless aggregate signature allows mapping nsignatures on n distinct messages from n distinct users into a single length signature. Recently Deng et al proposed CLAS Scheme which is an improvement ofHou et al scheme andclaims that their scheme is secure against type II adversary but unfortunately it is found unsecure by applying the Honest but Curious attack by adversary II. In this we show that Deng et al proposed scheme is insecure against type II adversary.