Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Coding for the Wiretap Channel
KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
2011 (Engelska)Licentiatavhandling, monografi (Övrigt vetenskapligt)
Abstract [en]

We consider code design for Wyner’s wiretap channel. Optimal coding schemes for this channel require an overall code that is capacity achieving for the main channel, partitioned into smaller subcodes, all of which are capacity achieving for the wiretapper’s channel. To accomplish this we introduce two edge type low density parity check (LDPC) ensembles for the wiretap channel. For the scenario when the main channel is error free and the wiretapper’s channel is a binary erasure channel (BEC) we find secrecy capacity achieving code sequences based on standard LDPC code sequences for the BEC. However, this construction does not work when there are also erasures on the main channel. For this case we develop a method based on linear programming to optimize two edge type degree distributions. Using this method we find code ensembles that perform close to the secrecy capacity of the binary erasure wiretap channel (BEC- WT). We generalize a method of M ́easson, Montanari, and Urbanke in order to compute the conditional entropy of the message at the wire- tapper. This conditional entropy is a measure of how much information is leaked to the wiretapper. We apply this method to relatively simple ensembles and find that they show very good secrecy performance.

Based on the work of Kudekar, Richardson, and Urbanke, which showed that regular spatially coupled codes are capacity achieving for the BEC, we construct a regular two edge type spatially coupled ensem- ble. We show that this ensemble achieves the whole capacity-equivocation region for the BEC-WT.

We also find a coding scheme using Arıkans polar codes. These codes achieve the whole capacity-equivocation region for any symmetric binary input wiretap channel where the wiretapper’s channel is degraded with respect to the main channel.

 

Ort, förlag, år, upplaga, sidor
Stockholm: KTH Royal Institute of Technology , 2011. , s. 101
Serie
Trita-EE, ISSN 1653-5146 ; 2011:026
Nationell ämneskategori
Telekommunikation
Identifikatorer
URN: urn:nbn:se:kth:diva-31579ISBN: 978-91-7415-927-1 (tryckt)OAI: oai:DiVA.org:kth-31579DiVA, id: diva2:404831
Presentation
2011-04-08, Q2, KTH, Osquldas väg 10, Stockholm, 13:15 (Engelska)
Opponent
Handledare
Forskningsfinansiär
ICT - The Next Generation
Anmärkning
QC 20110321Tillgänglig från: 2011-03-21 Skapad: 2011-03-18 Senast uppdaterad: 2011-10-30Bibliografiskt granskad

Open Access i DiVA

fulltext(799 kB)1594 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 799 kBChecksumma SHA-512
6fb6b6bc03527109f423ff362f515b90d3bde5e7d73b25083a412ac0da47a7af4986c0f9d77bec36a9455fc7234d3a66ba38cf9697c34b6ffd0e6390cd8fb22e
Typ fulltextMimetyp application/pdf

Sök vidare i DiVA

Av författaren/redaktören
Andersson, Mattias
Av organisationen
Kommunikationsteori
Telekommunikation

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 1594 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

isbn
urn-nbn

Altmetricpoäng

isbn
urn-nbn
Totalt: 910 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf