Verification is one of the pillars of arms control and non-proliferation treaties as well as an important part of confidence building measures. It defines practical measures that enable treaty members to check the treaty compliance by observing, counting or monitoring specific actions and their accordance with the respective rules. In contrast to historical examples of former military technologies, cyberspace features some unique characteristics making it hard to apply established measures. The chapter describes these peculiarities and assesses distinguishing problems compared to selected verification measures for nuclear, biological and chemicals weapons technology. Yet, cyberspace is a human-made domain and adjusting its technical setting, rules and principles may help to reduce the threat of ongoing militarisation. Offering some alternatives, the chapter elaborates on suitable and measurable parameters for this domain and presents potentially useful verification approaches.