- The verifier requests some amount of randomly placed file blocks from the replicator.
- The replicator generates blocks of passed file indexes and sends them to the verifier.
- The verifier compares its blocks with the replicator's blocks.
If there are any differences between the verifier's and the replicator's blocks, the replicator fails the Challenge, and it is banned by all signers of the contract. After that, the verifier searches for other replicators and asks them to send file data.