Efficient Identity-Based Parallel Key-Insulated Signature Scheme using Pairings over Elliptic Curves

Many cryptographic schemes were designed under the assumption that the private keys involved in the system are perfectly secure. If the private key of a signer is exposed then security of the system is totally lost. Key-insulation mechanism minimizes the damage caused by the exposure of private keys in cryptographic schemes. To deal with the key-exposure problem in ID-based schemes, private keys have to be updated at very short intervals; but it will increase the risk of helper key exposure. In order to improve the security and efficiency of key insulation mechanism in ID-based signatures, in this paper, we proposed an ID-based parallel key insulated signature scheme. This scheme uses the bilinear pairings over elliptic curves and is provably secure in the ROM model with the assumption that the CDH problem is intractable. This scheme is strong key-insulated and allows frequent key updates without increasing the risk of helper key exposure and hence improve the security of the system. Also our IDPKIS Scheme reduces the computational, communicational complexity and hence the scheme can be deployed on inexpensive, lightweight and mobile devices.