Public international law (advanced)¶

Public international law is the body of law governing relations between states. It generally seeks to regulate the behaviour of states rather than the actions of their residents or citizens. It also applies to intergovernmental organisations, but not to the constituent states of federal systems. Sources of law include treaties, widely accepted international norms and customs, as well as decisions of international courts. The most comprehensive and widely accepted source on the application of international law to cyber operations is the Tallinn Manual (v2.0 2017).

There are many types of cross-border cyber operations assessed under international law. Most are far more covert than cyber warfare. Even cyber warfare itself takes many forms, and one difficult issue is attribution. Cyber espionage, on the other hand, does not necessarily fall within the scope of international law if it is conducted by an entity other than a state actor.

Ordinary cybercrimes often require cross-border criminal investigations. The police of any given state generally lack physical jurisdiction within the territory of another state, but actions carried out in cyberspace, such as surveillance, may be more difficult to analyse. Although remote surveillance as such may not violate international law, methods of collecting evidence may infringe the sovereignty of another state and may also constitute an offence under that state’s national law. An example of this could be the remote takeover of a botnet controller or another device located within the territory of another state. Despite this, authorities at times engage in remote cyber surveillance and evidence collection with explicit or implicit authorisation from their government, even without the consent of the target state.