Decentralized Private Freight Declaration & Tracking with Data Validation

In January 2017, a truck crossed the border between Spain and France for the first time using an e-CMR: An electronic version of the primary transport document required for inter-European logistics. Since that crossing, researchers and logistic organizations have proposed a large number of ideas to further digitize Europe's supply chain. Many of these ideas involve blockchains, but not all of them validate the data that is posted to them. As a result, participants can make illegitimate claims: Even though the blockchain enables transparency and immutability of the data stores, it does not ensure veracity. We provide several examples of works about information sharing in the supply chain that do not perform such validation. One work that does use the blockchain's validation functionality is DEFEND. DEFEND addresses customs agencies' lack of information for international freight inspection by tracking shipping containers throughout their journey. As containers pass from one operator to another, the blockchain participants ensure that containers are not doubly spent. In this work, we propose an extension of DEFEND, in which we further extend the capabilities for validation. Moreover, we provide actual cryptographic protocols to preserve participants' privacy while DEFEND only described privacy on a high level. Finally, by making a more fine-grained distinction between different actors in the chain, we model the entire supply chain from buyer to seller. As a result, the buyer and seller can now track the respective package's whereabouts through each leg of its journey.