What are the advantages and disadvantages of implementing custom encryption methods in PHP scripts?

Implementing custom encryption methods in PHP scripts can provide enhanced security by allowing you to customize the encryption algorithm and key generation process. However, it also introduces the risk of creating vulnerabilities if the encryption method is not properly implemented or if the key management is weak. Additionally, custom encryption methods may not be as widely tested or supported as standard encryption algorithms, potentially leading to compatibility issues.

function customEncrypt($data, $key) {
    $iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length('aes-256-cbc'));
    $encrypted = openssl_encrypt($data, 'aes-256-cbc', $key, 0, $iv);
    return base64_encode($iv . $encrypted);
}

function customDecrypt($data, $key) {
    $data = base64_decode($data);
    $iv = substr($data, 0, openssl_cipher_iv_length('aes-256-cbc'));
    $encrypted = substr($data, openssl_cipher_iv_length('aes-256-cbc'));
    return openssl_decrypt($encrypted, 'aes-256-cbc', $key, 0, $iv);
}