The implemented designof ChronoShare uses an approach that treats indi-vidual user operations on les as streams of \ac-tions," where each action species which le hasbeen modied and what changes have been made,e.g., new le, updated content, changed le sys-tem permissions, or removed le (Figure 2.10). Ac-tions are carried in NDN data packets, thus they arenamed and signed, automatically adding ownershipinformation for each operation. By applying actionsfrom all participants in a deterministic order, in combination with the con ict resolution process described,each ChronoShare user can build her consistent up-to-date view of the shared folder and, when desired, fetchall missing les. The main advantage of this action-based approach is that, in typical shared folder usagescenarios, no matter how many changes a user might have made to the shared folder, there is a straightfor-ward way to propagate changes to other participants: Others just need to fetch all actions from the user andapply these actions to their folder. Actions by each user form a \stream" of data items, and the streamsfrom all users of a shared folder form a dataset that can be synchronized using the ChronoSync primitive.