Cryptology ePrint Archive: Report 2011/395

Improved Anonymity for Key-Trees

Beye, Michael and Veugen, Thijs

Abstract: Randomized hash-lock protocols for Radio Frequency IDentification (RFID) tags offer forward untraceability, but incur heavy search on the server. Key trees have been proposed as a way to reduce search times, but because partial keys in such trees are shared, key compromise affects several tags. Butty{\'a}n et al. have quantified the resulting loss of anonymity in the system, and proposed specific tree properties in an attempt to minimize this loss. We will further improve upon these results, and provide a proof of optimality. Finally, our proposals are compared to existing results by means of simulation.

Category / Keywords: cryptographic protocols / RFID, Hash-lock protocol, key-tree, anonymity, anonymity set

Date: received 22 Jul 2011

Contact author: m r t beye at tudelft nl

Available formats: PDF | BibTeX Citation

Version: 20110728:025555 (All versions of this report)

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