Group signature with time-bound keys and unforgeability of expiry time for smart cities

Abstract

Abstract Internet of Things (IoT) lays the foundation for the various applications in smart cities, yet resource-constrained IoT devices are prone to suffer from devastating cyberattacks and privacy leak threats, thus are inevitability supposed as the weakest link of the systems in smart cities. Mitigating the security risks of data and the computing limitation of edge devices, especially identity authentication and key validity management of group devices are essential for IoT system security. In order to tackle the issues of anonymity, traceability, unforgeability of expiry time as well as efficient membership revocation for life-cycle management of devices in IoT setting, we presented a dynamic time-bound group signature with unforgeability of expiry time. Unforgeability of expiry time disables a revoked signer to create a valid signature by means of associating the signing key with an expiry time. The anonymity and traceability of the proposed scheme contribute to the identity privacy of the entities and supervision for authority agency. Moreover, our proposal is feasible in the resource-constrained setting for efficient computational cost of signing and verification algorithms.

Keywords

• Group signatures
• Unforgeability of expiry time
• Time-bound keys
• Internet of things
• Smart cities