Ruhlman Enterprises, Inc.
In this paper a number of wide-spread authentication protocols (EM, HITAG, and KeeLoq IFF) used for component identification and automotive applications have been systematically treated. A consistent security analysis of these protocols has been performed with respect to standard attacks such as dictionary attacks or scan attacks. Moreover, an extension of the dictionary attack the authors call a three-step dictionary attack has been proposed for protocols with authenticated challenges (HITAG and EM). This allowed achieving a speed-up of over 20.000 with respect to the standard attacks for the HITAG protocols.