对称算法又称为传统密码算法。对称算法的对称性体现在加密密钥能够从解密密钥推算出来, 反之亦然。在大多数对称算法中, 加解密的密钥是相同的。可见, 对称密钥算法的加解密密钥都是保密的。对称密钥算法又分为两种分组密码和流密码。分组密码将明文分割为若干个定长的数据块称为一个分组, 每次对一个分组进行处理流密码又称序列密码, 依次对输人每个元素进行处理。DES算法是一种最通用的对称密钥算法, 属于分组密码算法。-Symmetric algorithm, also known as the tradit

用于蜂窝宽带的流和文件的RC5加密程序.包含数字签名,消息加扰等功能.-RC5 is a block cipher that was originally designed by Ronald Rivest (http://theory.lcs.mit.edu/~cis/pubs/rivest/rc5.ps). We have implemented and optimized the RC5 encryption/decryption library for the Sony-Toshiba-

实现了SSE（SSE简单流加密算法），该算法具有块加密与流密码特性的加密算法。-It implements SSE (SSE simple stream encryption algorithm), the algorithm has characteristics of stream ciphers and block cipher encryption algorithm.

BLAKE2 are cryptographic hash functions based on Dan Bernstein s Cha stream cipher, but a permuted copy of the input block, XORed with some round constants, is added before each Cha round. Like SHA-2, there are two variants differing in the word size