A Strong Designated Verifier Proxy Re-Signature Scheme for IoT Environments

With the rapid popularization of the Internet of Things (IoT) in our daily lives, the communication security and identity privacy of IoT devices must be ensured. However, traditional authentication mechanisms utilized in IoT cannot completely ensure a user’s privacy when his/her messages are routed via an untrusted intermediate device. Strong designated-verifier proxy re-signature (SDVPRS) is a new cryptographic technology that combines the advantages of strong designated verifier signature and proxy re-signature. Therefore, SDVPRS is considered to be a better approach to maintain data integrity and protect the identity privacy of the signer in a resource-limited IoT device. Nevertheless, designing a secure SDVPRS scheme without random oracles is still a challenging task. In this paper, we mainly focus on such a construction by providing a new method. We first provide the formal definition of SDVPRS and its security model. Then, we present the first SDVPRS scheme, which is bidirectional, multi-use and non-transferable, and we prove its security under the standard complexity assumptions in the standard model. The analysis results show that our SDVPRS scheme can not only protect the privacy of the signer’s identity, but also provide non-delegatability for signature verification. We present an example of potential application to environmental monitoring systems using our SDVPRS scheme