What are the security implications of encrypting and decrypting data within a PHP script, and how can this impact the overall security of the application, especially in the event of a server hack?

Encrypting and decrypting data within a PHP script can enhance security by protecting sensitive information from unauthorized access. However, storing encryption keys securely and ensuring proper implementation of encryption algorithms are crucial to prevent data breaches. In the event of a server hack, encrypted data may still be vulnerable if the encryption keys are compromised.

// Example of encrypting data using OpenSSL in PHP
$plaintext = "Sensitive information";
$encryption_key = openssl_random_pseudo_bytes(32);
$iv = openssl_random_pseudo_bytes(16);
$ciphertext = openssl_encrypt($plaintext, 'aes-256-cbc', $encryption_key, 0, $iv);

// Example of decrypting data using OpenSSL in PHP
$decrypted_text = openssl_decrypt($ciphertext, 'aes-256-cbc', $encryption_key, 0, $iv);
echo $decrypted_text;