International Association
for Cryptologic Research

This announcement is in connection with the recent IACR 2025 election conducted using the Helios electronic voting system. Regrettably, we have encountered a fatal technical problem that prevents us from concluding the election and accessing the final tally.

For this election and in accordance with the bylaws of the IACR, the three members of the IACR 2025 Election Committee acted as independent trustees, each holding a portion of the cryptographic key material required to jointly decrypt the results. This aspect of Helios’ design ensures that no two trustees could collude to determine the outcome of an election or the contents of individual votes on their own: all trustees must provide their decryption shares.

Unfortunately, one of the three trustees has irretrievably lost their private key, an honest but unfortunate human mistake, and therefore cannot compute their decryption share. As a result, Helios is unable to complete the decryption process, and it is technically impossible for us to obtain or verify the final outcome of this election.

This situation is visible on the public election page in Helios, where the trustees are listed: you can see that two trustees have successfully uploaded their decryption share material, whereas one has not. We point this out so that one can independently confirm that the issue arises from the strict cryptographic requirements of the system itself. You can consult this information at: https://vote.heliosvoting.org/helios/elections/e1130d04-aac6-11f0-95c8-3a40ecaef3ba/trustees/view

After careful consideration, we have decided that the only responsible course of action is to void this election and start a new election from scratch.

The new election will run from November 21 to December 20, using the same IACR membership electoral roll and the same list of candidates, which you can consult here: https://www.iacr.org/elections/2025/candidates.php

For all eligible voters, you will receive a separate Helios message inviting you to participate in the new run of the IACR 2025 election. Please note that if you opted out from Helios emails, we could not add you to the list of voters for the new election. In this case, you may opt back in at https://vote.heliosvoting.org/optin/ and send an email to elections@iacr.org to let us know, so that we can add you to the list of voters.

We are deeply sorry for this failure and for the disruption it has caused; this situation should not have happened, and we take it very seriously. We respectfully ask for your understanding and patience while we remedy the problem and ensure that the renewed process is as smooth, secure, and transparent as possible.

We are already drawing lessons from this incident and putting safeguards in place, so that it cannot reoccur. In particular, we will adopt a 2-out-of-3 threshold mechanism for the management of private keys, and we will circulate a clear written procedure for all trustees to follow before and during the election. Following the resignation of Moti Yung from his position as trustee for this election, he will be replaced by Michel Abdalla.

With our sincere apologies and best regards,

The IACR 2025 Election committee, with the approval of the IACR Board of Directors