DES算法的入口参数有三个：Key、Data、Mode。其中Key为8个字节共64位，是DES算法的工作密钥；Data也为8个字节64位，是要被加密或被解密的数据；Mode为DES的工作方式，有两种：加密或解密，如果Mode为加密，则用Key去把数据Data进行加密，生成Data的密码形式作为DES的输出结果；如Mode为解密，则用Key去把密码形式的数据Data解密，还原为Data的明码形式作为DES的输出结果。在使用DES时，双方预先约定使用的”密码”即Key，然后用Key去加密数据；接收方得到密文后使用同样的Key解密得到原数据，这样便实现了安全性较高的数据传输。-Entrance DES algorithm has three parameters: Key, Data, Mode. Key one of eight for a total of 64 bytes, are key job DES algorithm　Data for 8-byte 64-bit is to be encrypted or decrypted data　Mode work for DES, there are two types: encryption or decryption, if the Mode for encryption, the Key to the data with Data encryption, password Data generated forms of output as DES　such as Mode for decryption, the Key to put the password used forms of data Data to decrypt and restore for Data the form of the code output as DES. In the use of DES, the two sides agreed in advance to use the " password"　that is, Key, and then use the Key to encrypt data　ciphertext recipient received the Key to use the same raw data to be decrypted, thus achieve a higher degree of safety data.