Multi-tag and multi-owner RFID ownership transfer in supply chains

In any supply chain, there is a high likelihood for individual objects to change ownership at least once in their lifetime. As RFID tags enter the supply chain, these RFID-tagged objects should ideally be able to seamlessly accommodate ownership transfer issues while also accomplishing their primary intended purpose. Physical ownership transfer does not translate to strict ownership transfer in the presence of RFID tags given the wireless nature of communication with these tags. Moreover, whereas existing protocols implicitly assume a single tag that is owned by a single entity, it is not uncommon to encounter scenarios where tag ownership is shared among multiple entities. A dual of this is the case of an object with multiple tags. We consider ownership transfer scenarios for shared ownership transfer and single object with multiple RFID tags. In the multiple-tagged object case, we consider the possibility where objects gain and lose tags over time. We also present a protocol for simultaneous transfer of ownership of multiple tags between owners. Since ownership transfer without a trusted third party (TTP) is difficult to achieve, we propose a shared ownership sharing protocol and evaluate its properties.