Heterogeneous Signcryption Scheme Supporting Equality Test from PKI to CLC toward IoT

Abstract The prosperity of Internet of Things (IoT) has brought numerous advantages to individuals and organizations. Since the transmission channel is usually considered as untrusted, the notion of signcryption seems to be the desired method to ease the defect. Nevertheless, this primitive inevitably faces the new obstacle that how to search the required data without decrypting it. Therefore, inheriting the excellence of signcryption and equality test, we present a heterogeneous signcryption protocol supporting the equality test from public key infrastructure (PKI) to certificateless cryptosystem (CLC) toward IoT environment (PK‐CLET). In this way, the introduced construction not only preserves the integrity, confidentiality and unforgeability of data, but also allows the cloud server to perform the equality test on different ciphertexts. Moreover, the security of PK‐CLET as well as the performance evaluation are both shown that it is more suitable for IoT.