One-Time Anonymous Certificateless Signcryption Scheme Based on Blockchain

The rapid increase of users in the blockchain makes it possible to exchange a large amount of data every moment. Since the information published on blockchain is recorded and cannot be tampered with, there is the problem of leaking the real identity of users under the big data clustering attack. Meanwhile, the existing key generation center (KGC) needs a secure channel to transmit partial private keys, which makes partial private keys depending on the channel of interaction and creates a private key security problem. In this paper, we propose a one-time anonymous certificateless signcryption (OTACLSC) scheme based on blockchain. We securely use the public channel to improve the security of the private key. By constructing a one-time pseudonym public key in the blockchain to achieve anti-identity leakage, the communication initiator constructs the pseudonym public key of both communication parties to avoid the reuse of the pseudonym public key. Then we prove the security of the scheme under the random oracle model and compare it with other schemes. Our scheme has less computation cost and shorter ciphertext length while maintaining more reliable security.