Key exchange with unilateral authentication (short: unilateral key exchange) is an important primitive in practical security protocols; a prime example is the widely deployed TLS protocol, which is usually run in this mode. Unilateral key-exchange protocols are employed in a client-server setting where only the server has a certified public key. The client is then ...

The authors demonstrate relay attacks on Passive Keyless Entry and Start (PKES) systems used in modern cars. They build two efficient and inexpensive attack realizations, wired and wireless physical-layer relays that allow the attacker to enter and start a car by relaying messages between the car and the smart key. Their relays are completely independent ...