其实 php 有个Mcrypt库,自带很多加密函数, 只要自己弄个 密钥, 就可以进行可逆加密.
Here is a list of ciphers which are currently supported by the mcrypt extension. For a complete list of supported ciphers, see the defines at the end of mcrypt.h. The general rule with the mcrypt-2.2.x API is that you can access the cipher from PHP with MCRYPT_ciphername. With the libmcrypt-2.4.x and libmcrypt-2.5.x API these constants also work, but it is possible to specify the name of the cipher as a string with a call to mcrypt_module_open().