If a malicious block producer incorrectly computes the 2D Reed-Solomon code for a block's data, a fraud proof for this can be presented. We assume that the light clients have the AvailableDataHeader and the Header for each block. Hence, given a ShareProof, they can verify if the rowRoot or colRoot specified by isCol and position commits to the corresponding Share. Similarly, given the height of a block, they can access all elements within the AvailableDataHeader and the Header of the block.
If a malicious block producer incorrectly computes the state, a fraud proof for this can be presented. We assume that the light clients have the AvailableDataHeader and the Header for each block. Hence, given a ShareProof, they can verify if the rowRoot or colRoot specified by isCol and position commits to the corresponding Share. Similarly, given the height of a block, they can access all elements within the AvailableDataHeader and the Header of the block.