Two-hop secure communication using an untrusted relay

Aylin Yener, Xiang He

    Research output: Contribution to journalArticlepeer-review

    74 Scopus citations


    We consider a source-destination pair that can only communicate through an untrusted intermediate relay node. The intermediate node is willing to employ a designated relaying scheme to facilitate reliable communication between the source and the destination. Yet, the information it relays needs to be kept secret from it. In this two-hop communication scenario, where the use of the untrusted relay node is essential, we find that a positive secrecy rate is achievable. The center piece of the achievability scheme is the help provided by either the destination node with transmission capability, or an external good samaritan node. In either case, the helper performs cooperative jamming that confuses the eavesdropping relay and disables it from being able to decipher what it is relaying. We next derive an upper bound on the secrecy rate for this system. We observe that the gap between the upper bound and the achievable rate vanishes as the power of the relay node goes to infinity. Overall, the paper presents a case for intentional interference, that is, cooperative jamming, as an enabler for secure communication.

    Original languageEnglish (US)
    Article number305146
    JournalEurasip Journal on Wireless Communications and Networking
    StatePublished - 2009

    All Science Journal Classification (ASJC) codes

    • Signal Processing
    • Computer Science Applications
    • Computer Networks and Communications


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