Lightweight Certificateless Encryption Supporting Equality Test without Bilinear Pairing

Certificateless cryptography enjoys the advantages of simplified certificate management and no key escrow problem. Equality test allows one to judge whether two ciphertexts are generated from two same plaintexts or not without decrypting them. Both of thest two techniques rely heavily on the cryptographic tool, namely the bilinear pairing. However, the bilinear pairing requires more computational costs and is normally not suitable for lightweight devices. In this paper, we study how to construct certificateless encryption scheme that supports equality test without resorting to bilinear pairing. Our scheme combines the building blocks of pairing-free certificateless encryption and ciphertext equality test technique.