Cyber-attacks are a real challenge for international arbitration. In a multi-billion US$ post M&A dispute, internationally known under the label Eldorado case, the defeated party is requesting the State Court of Sao Paulo (Brazil) to set a partial award aside on the grounds, among others, that the successful counterparty took advantage of information, which was obtained by means of a cyber-attack. The challenge is in its early stages and, for the time being, the court maintains confidentiality of the case files. Thus, this article will and cannot discuss the Eldorado case specifically because there is no public access to the facts.

Therefore, the issue will be analyzed on the basis of a hypothetical scenario characterized by two assumptions: first, a cyber-attack took place, but it only surfaced after the arbitral award was rendered; and second, solely one party had access to the "fruits" of the attack and used it in the arbitral proceedings. Against this background I will discuss how the New York Convention on the Recognition and Enforcement of Foreign Arbitral Awards of 1958 (NY-Convention), and the UNCITRAL Model Law on International Commercial Arbitration (Model Law) should be applied; in other words, I will try to answer the question: Does the impact of a cyber-attack give grounds to deny exequatur of the award and/or to set it aside?

Consequently, this article will neither discuss how to prevent cyber-attacks nor how arbitrators should deal with it, if the issue surfaces along the arbitral proceedings. The second question poses, in my view, no new challenges. It raises the old task, how adjudicators should deal with evidence that was captured illicitly. In 2018, Edna Sussman brilliantly resumed the appropriate approach from an international arbitrator's perspective: "Where it is demonstrated that evidence has been obtained illegally the arbitral tribunal is faced with a difficult choice. (…) The decisions (regarding that choice) appear to emphasize who committed the wrongful act, whether the documents are privileged, and whether the information revealed was material to the decision on the merits. Balancing the search for truth and other values is not new. It is just being presented in a new context in our digital world." Edna Sussman, "Cyber Attacks: Issues Raised in Arbitration," NYSBA New York Dispute Resolution Lawyer, Vol. 11, No. 2, 2018, p. 10.