<?PHP
 
$string = "Some text to be encrypted";
$secret_key = "This is my SeCrEt key";
 
// Encryption Algorithm
$etype = MCRYPT_RIJNDAEL_256;
 
// Create the initialization vector for added security.
$iv = mcrypt_create_iv(mcrypt_get_iv_size($etype, MCRYPT_MODE_ECB), MCRYPT_RAND);
 
// Output original string
PRINT "Original string: $string <p>";
 
// Encrypt $string
$encrypted_string = mcrypt_encrypt($etype, $secret_key, $string, MCRYPT_MODE_CBC, $iv);
 
// Convert to hexadecimal and send to browser
PRINT "Encrypted string: ".BIN2HEX($encrypted_string)."<p>";
 
$decrypted_string = mcrypt_decrypt($etype, $secret_key, $encrypted_string, MCRYPT_MODE_CBC, $iv);
 
PRINT "Decrypted string is: $decrypted_string";
 
?>