Blockchain, the underlying technology of the Bitcoin cryptocurrency, is an innovation of information technology. The blockchain technology has been widely applied in the evidence storage scenarios to prove that an event occurred at a certain time due to its publicity and immutability. However, the timestamp of a block in the blockchain is introduced by the blockchain node and can be manipulated in hours. This will either lead the failure of the evidence storage system built on top of the blockchain platform or increase the risk of double spending of the blockchain platform itself. In this paper, we introduced an optimized blockchain timestamp mechanism. We narrow the range of the timestamp in a block to an average of ten minutes by leveraging an outside trust timestamp service to the blockchain consensus. Finally, we present a security analysis of the proposed scheme.

区块链是比特币加密货币的基础技术，是信息技术的创新。区块链技术已广泛应用于证据存储场景中，以证明事件由于其公开性和不可变性而在某个时间发生。但是，区块链中区块的时间戳是由区块链节点引入的，可以在数小时内进行操作。这将导致基于区块链平台构建的证据存储系统出现故障，或者增加区块链平台本身双重支出的风险。在本文中，我们介绍了一种优化的区块链时间戳机制。通过将外部信任时间戳服务用于区块链共识，我们将时间戳的范围平均缩小到十分钟。最后，