Attribution - tracing those responsible for a cyber attack - is of primary importance when classifying it as a criminal act, an act of war, or an act of terrorism. Three assumptions dominate current thinking: attribution is a technical problem; it is unsolvable; and it is unique. Approaching attribution as a problem forces us to consider it either as solved or unsolved. Yet attribution is far more nuanced, and is best approached as a process in constant flux, driven by judicial and political pressures. In the criminal context, courts must assess the guilt of criminals, mainly based on technical evidence. In the national security context, decision-makers must analyse unreliable and mainly non-technical information in order to identify an enemy of the state. Attribution in both contexts is political: in criminal cases, laws reflect society's prevailing norms and powers; in national security cases, attribution reflects a state's will to maintain, increase or assert its power. However, both processes differ on many levels. The constraints, which reflect common aspects of many other political issues, constitute the structure of the book: the need for judgement calls, the role of private companies, the standards of evidence, the role of time, and the plausible deniability of attacks.

ForewordAcknowledgements
Introduction
1. Modelling Attribution
Attribution by the executive: a set of conditions for the model
Two attribution processes: characteristics and deployed resources
2. Reliance on Judgement
Attribution as an inescapable judgement call
Political implications: authority and trust
3. Standards of Proof
Domestic and international legal standards for attribution: a mismatch
State sponsorship: malleable standards and misleading criteria
4. Private Companies
Three factors used to undermine companies' credibility
A non-negligible role on the international scene
5. Time
Measurable time: efforts to reduce it
Time in terms of context for national security incidents
6. Plausible Deniability
Sources of plausible deniability
Strategic considerations for warranting plausible deniability
Conclusion
Bibliography