The nahmii system is designed to allow any observer of the network to provide fraud proofs, which show that the Operator has committed fraud. This is trivial when the Operator has published a receipt detailing the fraud, but what happens if the Operator does not provide the data needed to create and submit fraud proofs? This challenge is known as the ‘Data Availability Problem’ and it is a major problem for second-layer scaling solutions like ours. Fortunately, we have a solution: enter the NII token.The NII token has a critical role in the nahmii protocol precisely because it will be used to reach consensus on whether all the relevant data was available pertaining to a particular settlement. If all data was made available by the Operator and it was all correct, a settlement attempt should be allowed.If data is missing then it is not generally possible to prove to our anti-fraud smart contracts that fraud took place, even though it might be obvious to a human observer. At the end of the challenge period, there should be consensus that data was missing and the settlement attempt should be prevented. This issue is the well known as the Data Availability Problem and is a notoriously difficult issue to solve.