We are happy to announce that from today the Keccak Crunchy Crypto Collision and Pre-image Contest re-opens without limit of time.

There are two minor changes.

• We have simplified the rules for the prizes. For all open challenges the first submission now simply receives 10 € multiplied by the number of rounds n_r. The challenges that have been closed remain closed.
• We allow for some more flexibility in choosing the reduced-round versions of Keccak-f. Previously, the n_r-round reduced-round version was fixed to the first n_r consecutive rounds. The submitters can now choose to take the last n_r consecutive rounds (as in the draft of FIPS 202) or any other n_r rounds, as long as they are consecutive.

We refer to Keccak Crunchy Crypto Collision and Pre-image Contest for more details.