Certificateless Aggregate Signcryption Scheme with Publicly Verifiable Pairless Operation
Chenhong Zhou · DOAJ (DOAJ: Directory of Open Access Journals) · 2022
Aggregate signcryption can combine ciphertext generated by different signcryption on different messages into a single ciphertext, which greatly reduces the total length of ciphertext and verification cost, and is more sui-table for low bandwidth and low storage communication environment. To solve the problems of poor security and inefficiency of aggregate signcryption with bilinear pairings in identity based cryptosystem, a new certificateless aggregate signcryption scheme which is based on a secure and efficient signature scheme and can be publicly verified without pair operation is designed. Hash function is used to bind the signcrypter’s identity information with part of the public key to generate part of the user’s private key to prevent public key replacement attacks. In the de-signcryption stage, the signcrypter’s identity information is taken as the output, which can verify the legitimacy of signcrypter’s identity and effectively hide it. In the random oracle model, the confidentiality and unforgeability of the scheme are reduced to the solving of computational Diffie-Hellman problem and discrete logarithm problem in polynomial time, which proves the security of the scheme. In the verification phase, any trusted third party can verify without any user’s private information, which proves the scheme has public verification. Furthermore, the efficiency of the scheme is compared. The proposed scheme only needs 3 n point multiplication operations in the aggregation de-signcryption stage, so it is more efficient.