Study on Security Analysis and Efficient Imrovement of Certificateless Aggregate Signature Scheme

In the traditional signature, anyone with the public key of the signer can verify the validation of a signature which is not suitable in some scenes where needs keeps the data privacy of the signer. Certificateless aggregate signature (CL-AS) scheme solves the problem with two part private keys from key generation center and the signer. CL-AS can also reduce the signature verification cost due to the aggregation property. In this manuscript, we first give a security analysis on a CL-AS scheme proposed recently. The analysis give a detail describe on two types of attacks on this CL-AS scheme which shows that the scheme is not secure and a malicious enemy can forgeabile an aggregate signature. Finally, we also present an improved CL-AS scheme. The improved scheme not only can overcome the existed security problem but also almost keeps the original efficiency. The scheme needs not bilinear pair operation and the computation cost is low, therefore the scheme can be applied into many fields, such as ad-hoc network, sensor network, and vehicular network.