Testbed Implementation of a Secure Flooding Time Synchronization Protocol

Abstract

A fundamental building block in distributed wireless sensor networks is time synchronization. Given resource constrained nature of sensor networks, previous research has focused on developing various energy efficient time synchronization protocols tailored for these networks. However, many of these protocols have not been designed with security in mind. In this paper, we describe FTSP which is one of the major time synchronization protocols for sensor networks. We outline the adverse effects of the time synchronization attacks on some important sensor network applications, and explain the set of possible attacks on FTSP. We then propose a number of countermeasures to mitigate the effect of the security attacks. We implement these attack scenarios on a sensor network testbed and show the extent each attack is successful in desynchronizing the network. Finally, we implement the countermeasures on our sensor network testbed to validate their usefulness in mitigating security attacks. We show that adding a sequence number filter to the original FTSP helps mitigate the effect of attacks on this protocol.

A scalable multi-sink gradient-based routing protocol for traffic load balancing

“…• Security concern: As stated in [16], since the hardware of sensor nodes is not tamper-resistant, the attacker can control any sensor node through physical compromise and it can also acquire the secret keys to participate in legitimate inter-node communications. Even though some cryptographic protocols can be applied to inter-node communications, the attacker can still access the cryptographic keys through physical compromise in order to participate in the communications in a legitimate way.…”

Secured Flooding Time Synchronization Protocol

“…Combining with RANSAC algorithm, every node can filter out the outlier messages from malicious nodes. However, these methods may cause unstable linear regression because the data is from different nodes [5]. As a result, the root selection problem still remains an open issue in FTSP.…”

“…When any node receives this fake message, it would find the seqN um inside this message higher than all current records and thus selects the malicious node as its reference node. The countermeasure of this seqN um attack is to use seqN um filter introduced in [5]. This seqN um filter uses extended data structure to collect data from randomly chosen k nodes out of total n neighbors and choose the node with smallest seqN um as reference node.…”

“…Among these time synchronization protocol, FTSP is a practical one with implementation written in NesC language. However, study shows that FTSP is not been designed with security in mind [5] and it could be easily compromised by malicious nodes in a WSN. Gheorghe et al recently proposed a faulttolerant FTSP to defend the attack launched by a malicious node sending inconsistent global time [6], yet there are still other vulnerabilities needed to be solved.…”

“…Gheorghe et al recently proposed a faulttolerant FTSP to defend the attack launched by a malicious node sending inconsistent global time [6], yet there are still other vulnerabilities needed to be solved. In order to defend the existent attacks mentioned in [5], we develop several techniques after thoroughly analyzed the structure of FTSP. In this paper, we implement four new components into FTSP to filter out attacking packets from malicious node.…”