Accepted and promotedSHA-256, 38 rounds
Collision attack, cost 95.90. Accepted by the judges and the promoted best result on that board. The headline result.
Security research
Results
Labelled the way the judges label them. Accepted means approved by the judges and reviewers. In review means not yet final.
Accepted and promoted
First on the boardFirst entries on new boards
First entries when the organizers opened SHA-256 at 39 rounds, SHA3-256 at 7 rounds, BLAKE3 at 4 rounds, and Poseidon at rounds 3, 4 and 5.
First on the boardPoseidon, rounds 3 to 5: actual collisions
Poseidon is the hash function inside Zcash's Orchard protocol. On rounds 3 to 5 the team found actual collisions by running the attack to completion on real hardware, rather than estimating a cost. The round-5 run took about 6 hours on 16 cloud CPU cores.
In reviewBLAKE3, 2 rounds
From 85.4 down to 70.7. In review.
In reviewSHA3-256, 5 rounds
39.8, best on the board, with a further improvement to 37.5 submitted. In review.
In reviewSHA-256, 37 rounds
60.97, best on the board. In review.
Baseline, not a breakFull-round tracks, all four functions
When the organizers opened every round count up to the full functions, the team filed the first entry at the maximum number of rounds on all four tracks within about 45 minutes: SHA-256 at 64 rounds, SHA3-256 at 24, BLAKE3 at 7, and the full Poseidon hash. These are generic birthday-bound searches at about the cost of brute force. They are a baseline, not a break of the real functions.
Thousands of recorded experiments, dozens of tested and closed ideas, and a database of every judge ruling, used to learn what the reviewers accept.
Facts as of October 15, 2026. Results move daily during the contest. Every number here is one the judges or the program recorded; nothing here claims that SHA-256, SHA-3, BLAKE3 or Poseidon were broken.