基于NTRU格上可链接环签名的区块链隐私保护技术研究

针对区块链目前面临的两个问题：隐私保护问题和量子攻击问题，本课题对基于NTRU格上可链接环签名的区块链隐私保护技术进行研究。重点研究签名长度为Olog(M)（M为环中成员个数）的NTRU格上可链接环签名的构建及其在数字货币系统的应用。首先，采用GGH标准方法，基于NTRU格的CVP困难问题，构建NTRU格上的同态承诺方案；然后，在同态承诺方案基础上，构建NTRU格上的Sigma-协议，并将该协议通过Fiat-shamir转化技术转化为可链接环签名方案；最后，将NTRU格上可链接环签名替换目前数字货币系统的标准数字签名，并更新系统中相关的配套算法协议。本课题的研究相信对于促进密码学、金融领域和涉及区块链应用的其他领域的发展都具有积极意义。

Aiming at the two problems that Blockchain faces at present: privacy protection and quantum attack, we study the privacy protection technology of Blockchain based on the linkable ring signature from NTRU Lattice. This paper focuses on the construction of a linkable ring signature from NTRU Lattice with a signature length Olog(M) (M is the number of members in the ring) and its application in the digital money system. First of all, using the GGH standard method, based on the CVP hard problem in NTRU lattice, construct a homomorphic commitment scheme from NTRU Lattice ; then, construct a Sigma-protocol over NTRU Lattice based on the homomorphic commitment scheme, and transform the protocol into a linkable ring signature scheme through Fiat-shamir technology ; finally, replace the standard digital signature in existing digital currency system by the linkable ring signature over NTRU Lattice , and update the related protocol. The research of this project is believed to be of positive significance to the development of cryptography, finance and other fields involved in the application of Blockchain.