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

// Designate string to be encrypted
= "Applied Cryptography, by Bruce Schneier, is
a wonderful cryptography reference.";

// Encryption/decryption key
key = "Four score and twenty years ago";

// Encryption Algorithm
= MCRYPT_RIJNDAEL_128;

// Create the initialization vector for added security.
= mcrypt_create_iv(mcrypt_get_iv_size(,
MCRYPT_MODE_ECB), MCRYPT_RAND);

// Output original string
print "Original string:
";

// Encrypt
= mcrypt_encrypt(, key,
, MCRYPT_MODE_CBC, );

// Convert to hexadecimal and output to browser
print "Encrypted string: ".bin2hex()."

";

= mcrypt_decrypt(, key,
, MCRYPT_MODE_CBC, );

print "Decrypted string: ";

?>

Original string: Applied Cryptography, by Bruce Schneier, is a wonderful cryptography reference.

Encrypted string: 02a7c58b1ebd22a9523468694b091e60411cc4dea8652bb8072 34fa06bbfb20e71ecf525f29df58e28f3d9bf541f7ebcecf62b c89fde4d8e7ba1e6cc9ea24850478c11742f5cfa1d23fe22fe8 bfbab5e

Decrypted string: Applied Cryptography, by Bruce Schneier, is a wonderful cryptography reference.