Secure source coding with a helper

Ravi Tandon, Sennur Ulukus, Kannan Ramchandran

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

9 Scopus citations

Abstract

We consider a secure lossless source coding problem with a rate-limited helper. In particular, Alice observes an i.i.d. source Xn and wishes to transmit this source losslessly to Bob at a rate Rx. A helper, say Helen, observes a correlated source Yn and transmits at a rate Ry to Bob. A passive eavesdropper can observe the coded output of Alice. The equivocation Δ is measured by the conditional entropy H(X n|Jx)/n, where Jx is the coded output of Alice. We first completely characterize the rate-equivocation region for this secure source coding model, where we show that Slepian-Wolf type coding is optimal. We next study two generalizations of this model and provide single-letter characterizations for the respective rateequivocation regions. In particular, we first consider the case of a two-sided helper where Alice also has access to the coded output of Helen. We show that for this case, Slepian-Wolf type coding is suboptimal and one can further decrease the information leakage to the eavesdropper by utilizing the sideinformation at Alice. We finally generalize this result to the case when there are both secure and insecure rate-limited links from Helen and additional uncoded side informations Wn and Zn available at Bob and Eve, respectively. For this model, we provide a complete characterization of the rate-equivocation region when Yn → Xn → (Wn,Zn) forms a Markov chain.

Original languageEnglish (US)
Title of host publication2009 47th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2009
Pages1061-1068
Number of pages8
DOIs
StatePublished - 2009
Externally publishedYes
Event2009 47th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2009 - Monticello, IL, United States
Duration: Sep 30 2009Oct 2 2009

Publication series

Name2009 47th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2009

Other

Other2009 47th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2009
Country/TerritoryUnited States
CityMonticello, IL
Period9/30/0910/2/09

ASJC Scopus subject areas

  • General Computer Science
  • Control and Systems Engineering
  • Communication

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