关于DES加密之选择更新版

数据加密算法(Data Encryption Algorithm,DEA)是一种对称加密算法,很可能是使用最广泛的密钥系统,特别是在保护金融数据的安全中,最初开发的DEA是嵌入硬件中的。通常,自动取款机(Automated Teller Machine,ATM)都使用DEA。它出自IBM的研究工作,IBM也曾对它拥有几年的专利权,但是在1983年已到期后,处于公有范围中,允许在特定条件下可以免除专利使用费而使用。1977年被美国政府正式采纳。 DES的原始思想可以参照二战德国的恩格玛机,其基本思想大致相同。传统的密码加密都是由古代的循环移位思想而来,恩格玛机在这个基础之上进行了扩散模糊。但是本质原理都是一样的。现代DES在二进制级别做着同样的事:替代模糊,增加分析的难度。 DES的加密原理,是使用一个 56 位的密钥以及附加的 8 位奇偶校验位,产生最大 64 位的分组大小。这是一个迭代的分组密码,使用称为 Feistel 的技术,其中将加密的文本块分成两半。使用子密钥对其中一半应用循环功能,然后将输出与另一半进行“异或”运算;接着交换这两半,这一过程会继续下去,但最后一个循环不交换。DES 使用 16 个循环,使用异或,置换,代换,移位操作四种基本运算。 类似于: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当然,这些都是base64编码。那么,什么是base64呢? Base64是网络上最常见的用于传输8Bit字节代码的编码方式之一,大家可以查看RFC2045~RFC2049,上面有MIME的详细规范。Base64编码可用于在HTTP环境下传递较长的标识信息。例如,在Java Persistence系统Hibernate中,就采用了Base64来将一个较长的唯一标识符(一般为128-bit的UUID)编码为一个字符串,用作HTTP表单和HTTP GET URL中的参数。在其他应用程序中,也常常需要把二进制数据编码为适合放在URL(包括隐藏表单域)中的形式。此时,采用Base64编码不仅比较简短,同时也具有不可读性,即所编码的数据不会被人用肉眼所直接看到。 比如,编写一个“123”,得出的结果就是“MTIz”。

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转载自www.cnblogs.com/lovesoul/p/9091039.html