Common randomness and secret key generation with a helper

Imre Csiszár, Prakash Narayan

Research output: Contribution to journalArticle

197 Citations (Scopus)


We consider the generation of common randomness (CR), secret or not secret, by two user terminals with aid from a `helper' terminal. Each terminal observes a different component of a discrete memoryless multiple source. The helper aids the users by transmitting information to them over a noiseless public channel subject to a rate constraint. Furthermore, one of the users is allowed to transmit to the other user over a public channel under a similar rate constraint. We study the maximum rate of CR which can be thus generated, including under additional secrecy conditions when it must be concealed from a wiretapper. Lower bounds for the corresponding capacities are provided, and single-letter capacity formulas are obtained for several special cases of interest.

Original languageEnglish
Pages (from-to)344-366
Number of pages23
JournalIEEE Transactions on Information Theory
Issue number2
Publication statusPublished - Jan 1 2000

ASJC Scopus subject areas

  • Information Systems
  • Computer Science Applications
  • Library and Information Sciences

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