File updates under random/arbitrary insertions and deletions

Qiwen Wang, Viveck Cadambe, Sidharth Jaggi, Moshe Schwartz, Muriel Médard

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    4 Scopus citations


    A client/encoder edits a file, as modeled by an insertion-deletion (InDel) process. An old copy of the file is stored remotely at a data-centre/decoder, and is also available to the client. We consider the problem of throughput- and computationally-efficient communication from the client to the data-centre, to enable the server to update its copy to the newly edited file. We study two models for the source files/edit patterns: the random pre-edit sequence left-to-right random InDel (RPES-LtRRID) process, and the arbitrary pre-edit sequence arbitrary InDel (APES-AID) process. In both models, we consider the regime in which the number of insertions/deletions is a small (but constant) fraction of the original file. For both models we prove information-theoretic lower bounds on the best possible compression rates that enable file updates. Conversely, our compression algorithms use dynamic programming (DP) and entropy coding, and achieve rates that are approximately optimal.

    Original languageEnglish (US)
    Title of host publication2015 IEEE Information Theory Workshop, ITW 2015
    PublisherInstitute of Electrical and Electronics Engineers Inc.
    ISBN (Electronic)9781479955268
    StatePublished - Jun 24 2015
    Event2015 IEEE Information Theory Workshop, ITW 2015 - Jerusalem, Israel
    Duration: Apr 26 2015May 1 2015

    Publication series

    Name2015 IEEE Information Theory Workshop, ITW 2015


    Other2015 IEEE Information Theory Workshop, ITW 2015

    All Science Journal Classification (ASJC) codes

    • Electrical and Electronic Engineering
    • Computer Networks and Communications
    • Information Systems
    • Computational Theory and Mathematics


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