3DES又称Triple DES，是DES加密算法的一种模式，它使用3条56位的密钥对数据进行三次加密。数据加密标准（DES）是美国的一种由来已久的加密标准，它使用对称密钥加密法，并于1981年被ANSI组织规范为ANSI X.3.92。DES使用56位密钥和密码块的方法，而在密码块的方法中，文本被分成64位大小的文本块然后再进行加密。比起最初的DES，3DES更为安全。-3DES, also known as Triple DES, DES encryption algorithm is a model that uses three 56-bit key three times the data encryption. Data Encryption Standard (DES) is a long-standing United States encryption standard that uses symmetric key encryption method, and in 1981 organized by ANSI standard is ANSI X.3.92. 56-bit DES key and password using the block method, the method in the code block, the text is divided into 64-bit size of the text block and then encrypted. Than the original DES, 3DES is more secure.