  In our modern society comfort became a standard. This comfort, especially in
cars can only be achieved by equipping the car with more electronic devices.
Some of the electronic devices must cooperate with each other and thus they
require a communication channel, which can be wired or wireless. In these days,
it would be hard to sell a new car operating with traditional keys. Almost all
modern cars can be locked or unlocked with a Remote Keyless System. A Remote
Keyless System consists of a key fob that communicates wirelessly with the car
transceiver that is responsible for locking and unlocking the car. However
there are several threats for wireless communication channels.
  This paper describes the possible attacks against a Remote Keyless System and
introduces a secure protocol as well as a lightweight Symmetric Encryption
Algorithm for a Remote Keyless Entry System applicable in vehicles.
