  Data format reverse engineering commonly involves identifying conserved
format motifs. However, this process typically requires establishing a common
ordering for format elements across instances, particularly for formats using
type-(length)-value tuples or "chunk" encoding. It is useful to
\emph{unshuffle} chunks with common length statistics as a precursor to
identifying conserved internal structures. We formalize the unshuffling problem
and subsequently derive probabilistic bounds and outline corresponding
algorithms for it. We empirically demonstrate unshuffling and highlight
connections with the related class of synchronization problems.
