Cyber attacks on keyless smart cars using software-defined radio are explored. The document discusses how software-defined radio technologies like GNURadio and HackRF can be used to capture radio frequency signals from key fobs and replay them to unlock cars, demonstrating vulnerabilities. Potential threats are outlined, and the implementation of capturing frequencies and replaying them is described. Finally, mitigation approaches are proposed, including rolling code and KeeLoq encryption techniques, to prevent replay attacks.