PHP шифрование и дешифрование данных

<?php 
	define('ENCRYPTION_KEY', 'a77gygb86d144e3f080uyg887b61c7c2e43');
	 
	function encrypt($plaintext){
		$ivlen = openssl_cipher_iv_length($cipher="AES-128-CBC");
		$iv = openssl_random_pseudo_bytes($ivlen);
		$ciphertext_raw = openssl_encrypt($plaintext, $cipher, ENCRYPTION_KEY, $options=OPENSSL_RAW_DATA, $iv);
		$hmac = hash_hmac('sha256', $ciphertext_raw, ENCRYPTION_KEY, $as_binary=true);
		$ciphertext = base64_encode( $iv.$hmac.$ciphertext_raw );
		return $ciphertext;
	}
	function decode($ciphertext){
		$c = base64_decode($ciphertext);
		$ivlen = openssl_cipher_iv_length($cipher="AES-128-CBC");
		$iv = substr($c, 0, $ivlen);
		$hmac = substr($c, $ivlen, $sha2len=32);
		$ciphertext_raw = substr($c, $ivlen+$sha2len);
		$plaintext = openssl_decrypt($ciphertext_raw, $cipher, ENCRYPTION_KEY, $options=OPENSSL_RAW_DATA, $iv);
		$calcmac = hash_hmac('sha256', $ciphertext_raw, ENCRYPTION_KEY, $as_binary=true);
		if (hash_equals($hmac, $calcmac))
		{
		    return $plaintext;
		}
	}

	$_one = encrypt("starnetkhv@gmail.com");
	echo $_one;
	echo decode($_one);