Independent arbitrator jointly appointed by the parties to resolve a dispute, notably on the attribution of a cyber operation to a state in the LMA 5567 Hamilton variant.
The umpire is a dispute resolution mechanism drawn from Anglo-American arbitration law, by which both parties jointly appoint an independent third party with the requisite skills to render a binding decision. In the Hamilton variant of LMA 5567A, this mechanism is introduced specifically for disputes concerning the attribution of a cyber operation to a state. If the parties fail to resolve their disagreement on attribution within thirty days of the matter being raised, either party may submit the dispute to a competent and disinterested umpire with relevant experience in international law matters. The resulting decision is binding. Additionally, the clause provides for the suspension (tolling) of all limitation periods and defenses based on the passage of time until attribution is determined, protecting the rights of both parties during the proceedings. This mechanism increases the predictability of the claims process for contested cyber war events, but adds a potentially lengthy procedural layer (several months) between the loss and actual settlement.
Following a massive cyberattack attributed by some governments to China but not officially acknowledged by the government of the state where the affected systems are located, the insurer invokes the cyber war exclusion. The insured contests the attribution. Under the Hamilton variant, the parties have 30 days to reach agreement; failing that, an umpire specialized in international law is appointed. Their decision will be binding on both parties.
arbitre indépendant, tierce partie arbitrale, umpire clause, independent umpire