In what way does the use of outdated libraries like MCrypt pose security risks in PHP applications, and what alternative libraries can be recommended for encryption?

Using outdated libraries like MCrypt in PHP applications can pose security risks as these libraries may have known vulnerabilities that can be exploited by attackers. It is recommended to switch to modern encryption libraries like OpenSSL or libsodium, which have better security features and are actively maintained.

// Using OpenSSL for encryption in PHP
$data = 'Sensitive data to encrypt';
$key = 'SecretKey';

$method = 'aes-256-cbc';
$iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length($method));

$encrypted = openssl_encrypt($data, $method, $key, 0, $iv);
$decrypted = openssl_decrypt($encrypted, $method, $key, 0, $iv);

echo "Encrypted: " . $encrypted . "\n";
echo "Decrypted: " . $decrypted;