Chameleon all-but-one trapdoor functions(ABO-TDFs) were introduced by Lai et al. An important component of the existing constructions of chameleon ABO-TDFs based on the decisional Diffie-Hellman(DDH)assumption was the...Chameleon all-but-one trapdoor functions(ABO-TDFs) were introduced by Lai et al. An important component of the existing constructions of chameleon ABO-TDFs based on the decisional Diffie-Hellman(DDH)assumption was the chameleon hash functions. In this paper, we instantiate the first chameleon ABO-TDFs based on DDH free of chameleon hash functions.展开更多
随着区块链的迅速发展,上链数据不仅包括金融交易数据,还包括科技、文化、政治等多类数据.而在现有的区块链系统中,数据一旦上链便无法更改,可能会面临失效数据无法删除、错误数据无法修改等问题.因此,特定条件下可修改的区块链方案具...随着区块链的迅速发展,上链数据不仅包括金融交易数据,还包括科技、文化、政治等多类数据.而在现有的区块链系统中,数据一旦上链便无法更改,可能会面临失效数据无法删除、错误数据无法修改等问题.因此,特定条件下可修改的区块链方案具有广阔的应用前景.在POSpace(proof of space)共识机制下,基于陷门单向函数和新型区块链结构,提出了可修改的区块链方案.只要超过阈值数的节点同意,便可实现区块数据的合法修改,否则不能进行修改.除修改数据外,其余区块数据保持不变,全网节点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:只要选定合适的阈值,所提方案中,区块生成与数据修改的效率均很高,数据的修改并不改变区块之间的链接关系,具有现实可操作性.展开更多
基金the National Natural Science Foundation of China(Nos.61373153 and 61170229)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20110073110016)the Scientific Innovation Projects of Shanghai Municipal Education Committee(No.12ZZ021)
文摘Chameleon all-but-one trapdoor functions(ABO-TDFs) were introduced by Lai et al. An important component of the existing constructions of chameleon ABO-TDFs based on the decisional Diffie-Hellman(DDH)assumption was the chameleon hash functions. In this paper, we instantiate the first chameleon ABO-TDFs based on DDH free of chameleon hash functions.
文摘随着区块链的迅速发展,上链数据不仅包括金融交易数据,还包括科技、文化、政治等多类数据.而在现有的区块链系统中,数据一旦上链便无法更改,可能会面临失效数据无法删除、错误数据无法修改等问题.因此,特定条件下可修改的区块链方案具有广阔的应用前景.在POSpace(proof of space)共识机制下,基于陷门单向函数和新型区块链结构,提出了可修改的区块链方案.只要超过阈值数的节点同意,便可实现区块数据的合法修改,否则不能进行修改.除修改数据外,其余区块数据保持不变,全网节点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:只要选定合适的阈值,所提方案中,区块生成与数据修改的效率均很高,数据的修改并不改变区块之间的链接关系,具有现实可操作性.
