用C#处理数字证书 使用System.Security.Cryptography.X509Certificate名称空间 System.Security.Cryptography.X509Certificate名称空间特别重要,因为它提供了开发人员处理数字签名的那些类. 提供了读取一个X.509证书的代码,和 使用不对称加密加密与解密数据的代码-C# using digital certificates System.Security.Cryptogra phy.X509C

Playfair Cipher 1.not even the large number of keys in a monoalphabetic cipher provides security 2.one approach to improving security was to encrypt multiple letters 3.the Playfair Cipher is an example 4.invented by Charles Wheatstone in 1854

Caesar cipher is a simple substitution cipher where each letter in the plain text is replaced with a letter a fixed number of places down the aplhabet. EXAMPLE If the number of places to shift is 3, the letter A would be converted to ltter D. Usi