Verifying Protein Folds
Besides duplication as verification there are numerous other computational methods to ensure that the result is valid. Proprietary software is used for folding at home so one can safely assume that they check hashes on processors and files regularly. If integrity is broken (by a crash, memory corruption or God forbid injection) the software client side and server side trashes the result. One can imagine that faulty hardware or other problems can result in a ban from the servers.