National Natural Science Foundation of China (No.61272425, No.61572267);Open Project of Shandong Provincial Key Lobaratory of Computer Networks (No.SDKLCN-2013-03);Construction Development Project (No.JK2015-26)
Certificateless aggregate signature is proposed to solve the key escrow problem and the complex certificate management problem.If the private key of any signer is exposed
the certificateless aggregate signature generated by the users including this signer will no longer be secure.To mitigate the damages of key-exposure in certificateless aggregate signature
we firstly integrate the key isolation mechanism into certificateless aggregate signature
and proposed the definition of key-insulated certificateless aggregate signature and its security model.We give a practical scheme
which achieves the periodical update of the signer's secret key by the interaction with the helper.We prove the proposed scheme is secure in the random oracle model
i.e.
the scheme has key insulated security
strong key insulated security and secure key updates.