A data processing system including storage. The data processing system also includes at least one processor to generate output data using at least a portion of a first neural network layer and generate a key associated with at least the portion of the first neural network layer. The at least one processor is further operable to obtain the key from the storage and obtain a version of the output data for input into a second neural network layer. Using the key, the at least one processor is further operable to determine whether the version of the output data differs from the output data.