Directory Reconciliation

TL;DR

This paper introduces the problem of directory reconciliation, proposing efficient protocols for synchronizing different versions of file directories that allow for file renaming and relocation, based on advanced document exchange techniques.

Contribution

It develops new protocols for directory reconciliation using reductions to document exchange with edit distance and block moves, and introduces a novel protocol inspired by noisy binary search.

Findings

Protocols achieve efficient synchronization with reduced communication complexity.

New protocol for document exchange under edit distance with block moves uses $O(k \\log n)$ bits.

The methods handle file renaming and relocation without significant expense.

Abstract

We initiate the theoretical study of directory reconciliation, a generalization of document exchange, in which Alice and Bob each have different versions of a set of documents that they wish to synchronize. This problem is designed to capture the setting of synchronizing different versions of file directories, while allowing for changes of file names and locations without significant expense. We present protocols for efficiently solving directory reconciliation based on a reduction to document exchange under edit distance with block moves, as well as protocols combining techniques for reconciling sets of sets with document exchange protocols. Along the way, we develop a new protocol for document exchange under edit distance with block moves inspired by noisy binary search in graphs, which uses only $O(k \log n)$ bits of communication at the expense of $O(k \log n)$ rounds of communication.