The International Association of Cryptologic Research—the academic cryptography association that’s been putting conferences like Crypto (back when “crypto” meant “cryptography”) and Eurocrypt since the 1980s—had to nullify an online election when trustee Moti Yung lost his decryption key.

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.

The group will redo the election, but this time setting a 2-of-3 threshold scheme for decrypting the results, instead of requiring all three

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