中文摘要：

签密是一个能同时实现数字签名和公钥加密的密码原语,并且其数据量要远低于传统的先签名后加密的方法。基于编码的密码体制是后量子密码中的一个重要方案,具有较高的计算效率,但是有密钥量过大的问题。针对这一问题,文章尝试利用准循环低密度奇偶校验码,在随机预言机的模型下,构造了一个可证明安全的签密方案。由于QC-LDPC的校验矩阵的准循环特性,可以有效地减小密钥量,与传统的先签名后加密的方法相比,密文减少了15.7%,与“一石二鸟”等基于数论的签密方案相比,计算效率有较大提高。安全性表明,方案在随机预言机模型下能达到IND-CCA2和EUF-CMA安全。

英文摘要：

Signcryption is a cryptographic primitive that performs both the function of digital signature and public-key encryption, at a cost significantly lower than that required in the traditional signature-then encryption. Code based cryptography is an important scheme in post-quantum cryptography. Its computational efficiency is high but it has the drawback of large key. Aiming at solving this problem, a signcryption based on QC-LDPC was proposed the random oracle model. Because of the quasi cyclic property of the parity check matrix of QC-LDPC codes, the size of key can be efficiently reduced, and compared with the traditional approach of signature-then encryption, the ciphertext is 2 5 % less. And the computational efficiency is high than the signcryption based on number theory such as＂Two birds one stone＂. Security analyse show that it satisfies IND-CCA2 and EUF- CMA security under random oracle model.