Efficient and Provably Secure Certificateless Parallel Key-Insulated Signature Without Pairing for IIoT Environments

With the continuous development of the industrial Internet of Things (IIoT), many organizations opt for storing the data collected by smart devices on a cloud server for saving costs. Considering the untrusted nature of the communication channel, how to ensure the authenticity of data is an urgent matter to be solved. Certificateless signatures that can provide an authentication mechanism for the data seem to be a viable option to this problem. Nevertheless, the certificateless signature scheme proposed so far is either easy to be broken or inefficient. In this paper, a pairing-free and provably secure certificateless parallel key-insulated signature (CL-PKIS) scheme is put forward for securing the communication in the IIoT environment. Unlike previous work in this field, our scheme not only uses elliptic curves to maintain higher efficiency, but also implants key-insulated primitive to reduce the risk of key exposures. Besides, our scheme provides a parallel mechanism to make it more suitable for the IIoT environment, which was not available in previous solutions. Finally, the security of our CL-PKIS scheme is proved under the discrete logarithm assumption in the random oracle model.