The final tip to secure your cookies is to use encryption and decryption, which protect the confidentiality and privacy of the cookies. This can prevent attackers from reading or extracting sensitive information from the cookies. You can use encryption and decryption by applying a cryptographic algorithm and a secret key to the cookie content or using a library that supports them. For example, in PHP, you can use the openssl_encrypt and openssl_decrypt functions to encrypt and decrypt the cookie value:
$value = 'some data';
$key = 'some secret';
$iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length('aes-256-cbc'));
$encrypted = openssl_encrypt($value, 'aes-256-cbc', $key, 0, $iv);
$cookie = base64_encode($encrypted . ':' . $iv);
setcookie('name', $cookie, time() + 3600, '/', '', true, true, 'Strict', 3600);
$cookie = base64_decode($_COOKIE['name']);
list($encrypted, $iv) = explode(':', $cookie, 2);
$decrypted = openssl_decrypt($encrypted, 'aes-256-cbc', $key, 0, $iv);