A method includes retrieving a decode threshold number of encoded data slices, wherein codecs process, in an order, a data segment and the processed data segment is encoded into a set of encoded data slices. The method further includes decoding the decode threshold number of encoded data slices to recover the processed data segment. In a reversed order to the order, applying a first codec on the processed data segment to produce a first partially processed recovered data segment. When the first codec is a verifiable codec, the method further includes separating the first partially processed recovered data segment into an initial integrity value and a processed data segment. The method further includes calculating a new integrity value from the processed data segment. When the new integrity value substantially matches the initial integrity value, the method further includes indicating that the set of encoded data slices is authentic.