在本系列文章的前几部分,我们已经了解在Delphi程序中利用SQL Server 2000 XML特性的数据查询技术。我们也研究了如何在Delphi数据敏感控件中使用XML数据源。作为系列文章的最后一部分,我们将探讨有关利用SQL ServerXML特性进行数据插...在本系列文章的前几部分,我们已经了解在Delphi程序中利用SQL Server 2000 XML特性的数据查询技术。我们也研究了如何在Delphi数据敏感控件中使用XML数据源。作为系列文章的最后一部分,我们将探讨有关利用SQL ServerXML特性进行数据插入、更新、删除的话题。展开更多
Quantum communication provides an enormous advantage over its classical counterpart： security of communications based on the very principles of quantum mechanics. Researchers have proposed several approaches for user...Quantum communication provides an enormous advantage over its classical counterpart： security of communications based on the very principles of quantum mechanics. Researchers have proposed several approaches for user identity authentication via entanglement. Unfortunately, these protocols fail because an attacker can capture some of the particles in a transmitted sequence and send what is left to the receiver through a quantum channel. Subsequently, the attacker can restore some of the confidential messages, giving rise to the possibility of information leakage. Here we present a new robust General N user authentication protocol based on N-particle Greenberger-Horne-Zeilinger （GHZ） states, which makes eavesdropping detection more effective and secure, as compared to some current authentication protocols. The security analysis of our protocol for various kinds of attacks verifies that it is unconditionally secure, and that an attacker will not obtain any information about the transmitted key. Moreover, as the number of transferred key bits N becomes larger, while the number of users for transmitting the information is increased, the probability of effectively obtaining the transmitted authentication keys is reduced to zero.展开更多
文摘Quantum communication provides an enormous advantage over its classical counterpart： security of communications based on the very principles of quantum mechanics. Researchers have proposed several approaches for user identity authentication via entanglement. Unfortunately, these protocols fail because an attacker can capture some of the particles in a transmitted sequence and send what is left to the receiver through a quantum channel. Subsequently, the attacker can restore some of the confidential messages, giving rise to the possibility of information leakage. Here we present a new robust General N user authentication protocol based on N-particle Greenberger-Horne-Zeilinger （GHZ） states, which makes eavesdropping detection more effective and secure, as compared to some current authentication protocols. The security analysis of our protocol for various kinds of attacks verifies that it is unconditionally secure, and that an attacker will not obtain any information about the transmitted key. Moreover, as the number of transferred key bits N becomes larger, while the number of users for transmitting the information is increased, the probability of effectively obtaining the transmitted authentication keys is reduced to zero.
