Modelling a multichannel security protocol to address Man in the Middle attacks
Abstract
Unlike wired networks, wireless networks cannot be physically protected, mak
ing them greatly at risk. This study looks into advanced ways of implementing
security techniques in wireless networks. It proposes using model checking and the
orem proving to prove and validate a security protocol of data transmission over
multi-channel in Wireless Local Area Networks (WLANs) between two sources.
This can help to reduce the risk of wireless networks being vulnerable to Man
in the Middle (MitM) attacks. We model secure transmission over a two-host
two-channel wireless network and consider the transmission in the presence of a
MitM attack. The main goal of adding an extra channel to the main channel is
to provide security by stopping MitM from getting any readable data once one of
these channels has been attacked.
We analyse the model for vulnerabilities and specify assertions for secure data
transmission over a multi-channel WLAN. Our approach uses the model analyser
Alloy which uses a Satisfiability (SAT) solver to find a model of a Boolean formula.
Alloy characterizations of security models are written to analyse and verify that the
implementation of a system is correct and achieves security relative to assertions
about the model of our security protocol. Further, we use the Z3 theorem prover
to check satisfiability using the Satisfiability Modulo Theories (SMT) solver to
generate results. Using Z3 does not involve high costs and can help with providing
reliable results that are accurate and practical for complex designs.
We conclude that, based on the results we achieved from analysing our pro
tocol using Alloy and Z3 SMT solver, the solvers complement each other in their
strengths and weaknesses. The common weakness is that neither can tell us why
the model is inconsistent, if it is inconsistent. We suggest that an approach of be
ginning with modelling a problem using Alloy and then turning to prove it using
Z3, increases overall confidence in a model.