Biblio

Blockchain is a decentralized technology that provides untampered and anonymous security service to users. Without relying on trusted third party, it can establish the value transfer between nodes and reduce the transaction costs. Mature public key cryptosystem and signature scheme are important basis of blockchain security. Currently, most of the public key cryptosystems are based on classic difficult problems such as RSA and ECC. However, the above asymmetric cryptosystems are no longer secure with the development of quantum computing technology. To resist quantum attacks, researchers have proposed encryption schemes based on lattice recently. Although existing schemes have theoretical significance in blockchain, they are not suitable for the practical application due to the large size of key and signature. To tackle the above issues, this paper proposes an anti-quantum signature scheme over ideal lattice in blockchain. First, we transfer the signature scheme from the standard lattice to the ideal lattice, which reduces the size of public key. Afterwards, a novel signature scheme is proposed to reduce both the size of the private and public key significantly. Finally, we theoretically prove the security of our ideal lattice-based signature scheme with a reduction to the hardness assumption of Ideal Small Integer Sulotion problem which can resist quantum attacks. The efficiency analysis demonstrates that our signature scheme can be practically used in blockchain.