PCI DSS standard credit card encryption example with php

<?php

// Function to generate a random encryption key
function generateEncryptionKey($length = 32)
{
    return bin2hex(random_bytes($length));
}

// Function to encrypt credit card information
function encryptCreditCard($creditCardNumber, $encryptionKey)
{
    $iv = openssl_random_pseudo_bytes(16); // Initialization Vector

    // Encrypt the credit card number using AES-256-CBC algorithm
    $encryptedCreditCard = openssl_encrypt(
        $creditCardNumber,
        'aes-256-cbc',
        $encryptionKey,
        0, // Options
        $iv
    );

    // Return encrypted data along with the initialization vector
    return base64_encode($iv . $encryptedCreditCard);
}

// Function to decrypt credit card information
function decryptCreditCard($encryptedCreditCard, $encryptionKey)
{
    // Decode the base64-encoded string
    $decodedData = base64_decode($encryptedCreditCard);

    // Extract the initialization vector and encrypted credit card data
    $iv = substr($decodedData, 0, 16);
    $encryptedCreditCardData = substr($decodedData, 16);

    // Decrypt the credit card number using AES-256-CBC algorithm
    $decryptedCreditCard = openssl_decrypt(
        $encryptedCreditCardData,
        'aes-256-cbc',
        $encryptionKey,
        0, // Options
        $iv
    );

    return $decryptedCreditCard;
}

// Example usage
$creditCardNumber = '4111111111111111'; // Replace with actual credit card number
$encryptionKey = generateEncryptionKey();

// Encrypt the credit card number
$encryptedCreditCard = encryptCreditCard($creditCardNumber, $encryptionKey);

// Decrypt the credit card number
$decryptedCreditCard = decryptCreditCard($encryptedCreditCard, $encryptionKey);

// Display results
echo "Original Credit Card Number: $creditCardNumber\n";
echo "Encrypted Credit Card Number: $encryptedCreditCard\n";
echo "Decrypted Credit Card Number: $decryptedCreditCard\n";

?>