Secret sharing based unidirectional key distribution with dummy tags in Gen2v2 RFID-enabled supply chains

Recently, a secret sharing scheme is found to be effective to solve the key distribution problem between parties in RFID-enabled supply chains. However, there is a problem that an attacker might recover the legitimate key by collecting sufficient secret shares when products are carried in the public transportation. In this paper, we propose an effective secret sharing scheme by introducing sufficient number of dummy tags which possess a bogus secret share when the tag-attached products are conveyed. Since an attacker cannot see the tags themselves from the outside of the carrying vehicle, he/she cannot distinguish between the legitimate tags and dummy tags and thus has to find out the correct key by iteratively trying each combination of secret shares. On the other hand, the party who receives products can distinguish dummy tags since they are not attached to any product. We also adopt a file privilege and untraceable option which are newly ratified by Gen2v2 (Gen2 version 2) to realize secure and practical RFID-enabled supply chains. We prove that our construction is secure in both the privacy and robustness aspect. We also confirm that our scheme is easily implemented with the off-the-shelf RFID reader and tags.