PHP - Encriptar email en un enlace url

function desencriptar($valor,$method,$clave,$iv){

return  openssl_decrypt($valor, $method, $clave, false, $iv);

}

function encriptar($valor,$method,$clave,$iv){

return  openssl_encrypt($valor, $method, $clave, false, $iv);

}

$email = "CCCCCCCCC@DDD.ES";

$y = encriptar($email, METHOD_ENCRIPT[0], CLAVE_ENCRIPT[0], IV_ENCRIPT);

$z = desencriptar($y, METHOD_ENCRIPT[0], CLAVE_ENCRIPT[0], IV_ENCRIPT);

echo $z; //funciona

$y = "GQAGmUZjTauGYE7GF1Tz145ZZ2bD2b1TC33okzuwSIk=";

 $z = desencriptar($y, METHOD_ENCRIPT[0], CLAVE_ENCRIPT[0], IV_ENCRIPT);

 echo $z; //No funciona

METHOD_ENCRIPT[0] ??

CLAVE_ENCRIPT[0] ??

IV_ENCRIPT ??

define("METHOD_ENCRIPT",array('aes-256-cbc'));

define("TBL_DIRECCION", "direccion");

"INSERT INTO ".TBL_DIRECCION." (idDireccion, calle, numeroPortal, ptr, codigoPostal, ciudad, .........

define("DB_PASSWORD", "987654321");

$con = new PDO(DB_DNS, DB_USERNAME, DB_PASSWORD,$utf);

// <= Quitar esto para probar /*

$email = "CCCCCCCCC@DDD.ES";

echo "<br>Original String: " . $email;

// Store the cipher method

$ciphering = 'aes-256-cbc';//"AES-128-CTR";

// Use OpenSSl Encryption method

$iv_length = openssl_cipher_iv_length($ciphering);

$options = 0;

$encryption_iv = '1234567891011121';

// Store the encryption key

$encryption_key = "TuKey"; //SOLUCION

$encryption = openssl_encrypt($email, $ciphering,

            $encryption_key, $options, $encryption_iv);

echo "<br>Encrypted String: " . $encryption . "\n";

// Prueba

/* <= Quitar esto para probar*/

$encryption = 'IBKFqI4KD0si27cZTp4V7w==';

$ciphering = "AES-128-CTR";

$options = 0;

// Non-NULL Initialization Vector for decryption

$decryption_iv = '1234567891011121';

// Store the decryption key

$decryption_key = "TuKey"; //SOLUCION

// Use openssl_decrypt() function to decrypt the data

$decryption=openssl_decrypt ($encryption, $ciphering,

        $decryption_key, $options, $decryption_iv);

echo "<br>Decrypted String: " . $decryption;