RSA

RSA is the Rivest–Shamir–Adleman algorithm, a widely used method of encryption in the field of cryptography.

RSA is a public-key cryptosystem, with a public key, shared with everyone, and a private key, kept secret.

<?php

    // 1) Create a new private/public key pair
    $config = [
        'private_key_bits' => 2048,
        'private_key_type' => OPENSSL_KEYTYPE_RSA,
    ];
    
    $res = openssl_pkey_new($config);
    
    // Export the private key
    openssl_pkey_export($res, $privateKey);
    
    // Extract the public key
    $keyDetails = openssl_pkey_get_details($res);
    $publicKey = $keyDetails['key'];
    
    echo "Private Key:\n$privateKey\n\n";
    echo "Public Key:\n$publicKey\n\n";
    
    // 2) Encrypt a message
    $data = 'Hello, RSA!';
    
    // Encrypt with public key
    openssl_public_encrypt($data, $encrypted, $publicKey);
    
    // Encode for safe output/storage
    $encryptedBase64 = base64_encode($encrypted);
    
    echo "Encrypted:\n$encryptedBase64\n\n";

?>

Documentation

See Also

• openssl_public_encrypt

Related

• Base 64 Encoding
• XXTEA