How to use the Mcrypt extension library for encryption and decryption_PHP tutorial

Summary: Mcrypt 2.4.7 is a powerful encryption algorithm extension library, which includes 22 algorithms, including the following algorithms: ????Blowfish RC2 Safer-sk64 xtea ????Cast-256 RC4 Safer-sk128 ????DES RC4-iv Serpent ????Enigma Rijndael-128 Threeway ????Gost Rijndael-192 TripleDES ????LOKI97 Rijndael-256 Twofish ????PanamaSaferplus Wake ??How to install Mcrypt ? ??Mcrypt is not included in the standard PHP software package, so you need to download it. The download address is: ftp://argeas.cs-net.gr/pub/unix/mcrypt/. After downloading, compile it as follows and extend it in PHP: Download the Mcrypt software package.
???gunzipmcrypt-x.x.x.tar.gz ????tar -xvfmcrypt-x.x.x.tar ????./configure --disable-posix-threads ????make ????make install ?? ??cd to your PHP directory. ????./configure -with-mcrypt=[dir] [--other-configuration-directives] ????make ????make install ??According to your requirements and Make appropriate modifications to the server during PHP installation.
??How to use the Mcrypt extension library to encrypt data? ??First, we will introduce how to use the Mcrypt extension library to encrypt data, and then how to use it to decrypt. The following code demonstrates this process. It first encrypts the data, then displays the encrypted data on the browser, restores the encrypted data to the original string, and displays it on the browser.
??Use Mcrypt to encrypt and decrypt data????"; ????$decrypted_string = mcrypt_decrypt($ cipher_alg, $key, ????$encrypted_string, MCRYPT_MODE_CBC, $iv); ????print "Decrypted string: $decrypted_string"; ????> ??Executing the above script will produce the following output : ????Original string: Applied Cryptography, by Bruce Schneier, is a wonderful cryptography reference. ????Encrypted string: 02a7c58b1ebd22a9523468694b091e60411cc4dea8652bb8072 34fa06bbfb20e71ecf525f29df58e28f3d9bf5 41f7ebcecf62b c89fde4d8e7ba1e6cc9ea24850478c11742f5cfa1d23fe22fe8 bfbab5e ????Decrypted string: Applied Cryptography, by Bruce Schneier, is a wonderful cryptography reference. The two most typical functions in the above code are mcrypt_encrypt() and mcrypt_decrypt(), and their uses are obvious. We used the "Telegraph Codebook" mode. Mcrypt provides several encryption methods. Since each encryption method has specific characters that can affect the security of the password, you need to understand each mode. For those readers who have not been exposed to cryptography systems, the crypt_create_iv() function is more interesting. We will mention the initialization vector (hence, iv) it creates, which makes each message independent of each other.
Although not all modes require this initialization variable, PHP will give a warning message if this variable is not provided in the required mode.

http://www.bkjia.com/PHPjc/631053.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/631053.htmlTechArticleOverview: Mcrypt 2.4.7 is a powerful encryption algorithm extension library, which includes 22 algorithms, including It includes the following algorithms: ????Blowfish RC2 Safer-sk64 xtea ????Cast-256...