我想使用非對稱密鑰加密和解密字符串。由于字符串可以更大，我決定嘗試這樣的混合解決方案：<?phpuse phpseclib\Crypt\RSA;use phpseclib\Crypt\Rijndael;use phpseclib\Crypt\Random;function generateKeys(){    $rsa = new RSA();    return $rsa->createKey();}function encrypt($plaintext, $asym_key, $key_length = 150){    $rsa = new RSA();    $rij = new Rijndael();    $sym_key = Random::string($key_length);    $rij->setKey($sym_key);    $ciphertext = $rij->encrypt($plaintext);    $ciphertext = base64_encode($ciphertext);    $rsa->loadKey($asym_key);    $sym_key = $rsa->encrypt($sym_key);    $sym_key = base64_encode($sym_key);    $len     = strlen($sym_key);    $len         = dechex($len);    $len = str_pad($len, 3, '0', STR_PAD_LEFT);    $message = $len.$sym_key.$ciphertext;    return $message;}function decrypt($message, $asym_key){    $rsa = new RSA();    $rij = new Rijndael();    $len     = substr($message, 0, 3);    $len     = hexdec($len);    $sym_key = substr($message, 0, $len);    $message    = substr($message, 3);    $ciphertext = substr($message, $len);    $ciphertext = base64_decode($ciphertext);    $rsa->loadKey($asym_key);    $sym_key = base64_decode($sym_key);    $sym_key = $rsa->decrypt($sym_key);    // Decrypt the message    $rij->setKey($sym_key);    $plaintext = $rij->decrypt($ciphertext);    return $plaintext;}$keys      = generateKeys();$encrypted = encrypt('test', $keys['publickey']);print_r($encrypted);$decrypted = decrypt($encrypted, $keys['privatekey']);print_r($decrypted);