SQIsign2DPush: Faster Signature Scheme Using 2-Dimensional Isogenies
摘要
Isogeny-based cryptography involves cryptographic schemes whose security is based on the hardness of a mathematical problem called the isogeny problem and is attracting attention as one of the candidates for post-quantum cryptography. A representative isogeny-based cryptography is the signature scheme called SQIsign, which was submitted to the NIST PQC standardization competition for additional signature. SQIsign has attracted much attention because of its very short signature and key size among candidates for the NIST PQC standardization. Recently, many new signature schemes using high-dimensional isogenies have been proposed, such as SQIsignHD, SQIsign2D-West, SQIsgn2D-East, and SQIPrime. Last year, SQIsign advanced to Round 2 of the NIST competition and was updated to version 2.0 (we call it SQIsign-v2.0), which is based on SQIsign2D-West. SQIsign-v2.0 achieves smaller signature sizes and faster verification. However, the signing costs are relatively high. In this paper, we propose a new signature scheme named ‘SQIsign2DPush’, which has a smaller signing cost than SQIsign-v2.0 (without Qlapoti) while the signature size and the verification cost are almost the same.