基于区块链的身份认证机制的效率优化方法研究

基于区块链的去中心化PKI使用区块链替代传统的CA，借助区块链的权威性和公开性，实现了认证的去中心化。目前的研究大多使用遍历区块链的方法查询身份—公钥对，从而验证某公钥是否属于通信对方，效率较低。提出了一种基于密码累加器的身份认证方式，将链上身份和公钥信息映射为累加值，实现认证功能的同时提高了身份—公钥对的验证效率，同时解决了区块链体积不断增长的情况下轻节点存储空间不够的问题，并通过实验验证了该方法的可行性和有效性。

Research on methods of improving efficiency of identity authentication based on blockchain

Decentralized public key infrastructure based on blockchain abandons certificate authority. With authoritativeness and publicity of the blockchain, this infrastructure is able to implement decentralized identity authentication. Many researches chose to traverse the entire blockchain to look up for a specific ID-PK pair and then verify whether the public key belongs to someone who claims it. However, this method is obviously inefficient. This paper proposed an identity authentication method based on cryptographic accumulators, which map identity, public key and auxiliary information to one accumulated value. This method improved the authentication efficiency, especially when current blockchain was large. In addition, it solved the problem that lightweight clients do not had enough storage capacity when the size of blockchain was continuously increasing. It also carried out some experiments to measure this method. It verifies its feasibility and correctness.