Mitigating the ACK counterfeiting attack in Delay and Disruption Tolerant Networks

Routing protocols for Delay and Disruption Tolerant Networks (DTNs) are prone to suffer from malicious behavior of nodes. Particularly, in the acknowledgment counterfeiting attack, malicious nodes forge acknowledgments in order to negatively impact network performance by removing from buffer messages that were not yet delivered to the destination. This paper proposes a new buffer management mechanism as a countermeasure against the acknowledgement counterfeiting attack in DTNs. The mechanism does not immediately drop acknowledged messages but it will drop these messages first if the buffer is full. Our mechanism also does not rely in any authentication method because we do not try to identify malicious nodes. The analysis considers traces of three real networks and results show our proposal mitigates the attack because the number of malicious nodes do not reduce the delivery rate. In addition, the proposed countermeasure outperforms the main countermeasure against this kind of attack found in literature, providing higher delivery rates up to 142%.