Discouraging Traffic Remapping Attacks in Local Ad Hoc Networks

Quality of Service (QoS) is usually provided in ad hoc networks using a class-based approach which, without dedicated security measures in place, paves the way to various abuses by selfish stations. Such actions include traffic remapping attacks (TRAs), which consist in claiming a higher traffic priority, i.e., false designation of the intrinsic traffic class so that it can be mapped onto a higher-priority class. In practice, TRAs can be executed in IEEE 802.11 ad hoc networks using the Enhanced Distributed Channel Access (EDCA) function. This attack is easy to perform yet hard to prevent. We propose a distributed discouragement scheme based on the threat of TRA detection and punishment. The scheme does not rely on station identities or a trusted third party, nor does it require tampering with the MAC protocol. We analyze an arising non-cooperative TRA game and find that under certain realistic assumptions it only incentivizes TRAs if they are harmless to other stations; otherwise the selfish stations are induced to learn that TRAs are counterproductive.