提出了一个新的基于RSA的不可否认签名方案,该方案的确认协议和否认协议是三次传递的,因而提高了效率。该方案同时实现了可转换性,可以把不可否认签名方案转换成通常的RSA数字签名方案。方案在随机问答器模型下证明是安全的,其不可伪造...提出了一个新的基于RSA的不可否认签名方案,该方案的确认协议和否认协议是三次传递的,因而提高了效率。该方案同时实现了可转换性,可以把不可否认签名方案转换成通常的RSA数字签名方案。方案在随机问答器模型下证明是安全的,其不可伪造性等同于CDH(Computational D iffie-Hellman)问题;不可分辨性等同于DDH(Decisional D iffie-Hellman)问题;不可扮演性等同于离散对数问题。展开更多
It has been claimed in the literature that impossibility of faster-than-light quantum communication has an origin of indistinguishability of ensembles with the same density matrix. We show that the two concepts are no...It has been claimed in the literature that impossibility of faster-than-light quantum communication has an origin of indistinguishability of ensembles with the same density matrix. We show that the two concepts are not related.We argue that even with an ideal single-atom-precision measurement, it is generally impossible to produce two ensembles with exactly the same density matrix; or to produce ensembles with the same density matrix, classical communication is necessary. Hence the impossibility of faster-than-light communication does not imply the indistinguishability of ensembles with the same density matrix.展开更多
文摘提出了一个新的基于RSA的不可否认签名方案,该方案的确认协议和否认协议是三次传递的,因而提高了效率。该方案同时实现了可转换性,可以把不可否认签名方案转换成通常的RSA数字签名方案。方案在随机问答器模型下证明是安全的,其不可伪造性等同于CDH(Computational D iffie-Hellman)问题;不可分辨性等同于DDH(Decisional D iffie-Hellman)问题;不可扮演性等同于离散对数问题。
文摘It has been claimed in the literature that impossibility of faster-than-light quantum communication has an origin of indistinguishability of ensembles with the same density matrix. We show that the two concepts are not related.We argue that even with an ideal single-atom-precision measurement, it is generally impossible to produce two ensembles with exactly the same density matrix; or to produce ensembles with the same density matrix, classical communication is necessary. Hence the impossibility of faster-than-light communication does not imply the indistinguishability of ensembles with the same density matrix.