Page 255 - 《软件学报》2020年第12期

任艳丽 等:可修改的区块链方案 3921

耗时分别为 3.8404s 和 1.1984s,区块修改耗时不超过区块生成耗时的 1/3,具有可操作性.
Table 4 Time of block generation and modification under the threshold of 80%
表 4 阈值比例为 80%时区块生成和修改耗时
耗时(s) 区块 1 区块 2 区块 3 区块 4 区块 5 平均
生成区块 3.826 2 3.833 6 3.841 4 3.852 4 3.848 5 3.840 4
修改区块 1.198 5 1.146 7 1.158 1 1.262 4 1.226 4 1.198 4
4 结 论
本文在 POSpace 共识机制下,基于陷门单向函数,提出了可修改的区块链方案.通过引入机动因子,重构区块
的签名子块,在区块数据需要修改时,只要特定阈值数的节点同意,便可实现区块数据的合法修改,且不破坏区
块的链接结构,全网仍可按原始验证方式对数据合法性进行验证.仿真实验表明:区块修改不超过区块生成耗时
的 1/3,具有可操作性.同时,阈值的设定使得恶意的非法修改无法完成,保证了数据修改的安全性.因此,可修改的
区块链可兼顾数据修改的安全性与执行效率,使区块链系统更加完善,适用性更强.

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