How can asymmetric encryption be implemented in PHP for secure data transfer?

To implement asymmetric encryption in PHP for secure data transfer, we can use the OpenSSL library. This library provides functions for generating key pairs, encrypting and decrypting data using public and private keys. By generating a key pair, encrypting the data with the recipient's public key, and decrypting it with our private key, we can securely transfer sensitive information over insecure networks.

// Generate key pair
$privateKey = openssl_pkey_new();
openssl_pkey_export($privateKey, $privateKeyStr);
$publicKey = openssl_pkey_get_details($privateKey)['key'];

// Encrypt data with recipient's public key
$data = "Sensitive information";
openssl_public_encrypt($data, $encryptedData, $publicKey);

// Decrypt data with our private key
openssl_private_decrypt($encryptedData, $decryptedData, $privateKey);

echo $decryptedData; // Output: Sensitive information