## Appendix A Background  
### The Overview of the Legacy NAS (NFC-Enabled Anti-Counterfeiting System)  
NAS with centralised data architectures which are predominantly based on the typical and familiar cloud-based client-server architecture style is demonstrated in Figure 11.  
The whole NAS solution consists of FIVE main components, which are (1) the back-end system with the web-based database management user interface for wine data management, for which the management of data columns of specific wine products in their custody can be performed by winemakers, (2) an NFC-enabled mobile application, _ScanWINE_, for the tag-reading purpose of wine products at retailer points for wine consumers, or supply chain participants of the supply chain, before accepting a wine product, (3) another NFC-enabled mobile application, _TagWINE_, performing tag-writing for wine products at the wine-bottling stage, (4) the NFC tags packaged on the bottleneck for those purposes and actions, and (5) any NFC-enabled smartphones or tablets of supply chain participants and wine consumers along the supply chain.  
There are FOUR major categories of data that are processed along the supply chain with NAS, namely, (1) nodal transaction history data, (2) supply chain data, (3) wine pedigree data, which is processed with its dedicated controllers based on their predefined schema and data models, and (4) unsuccessful validation data, returned from any unsuccessful validation at the stage of accepting wine products. The wine products are processedand handled by different nodes along the supply chain, with the data updated by scanning the NFC tags of the wine product using the tag-reading _ScanWINE_ and the wine record updated according to the database. These categories of data are updated along the supply chain until the point of purchase, where wine consumers use the tag-reading _ScanWINE_ to scan the NFC tags and retrieve, for example, as wine pedigree data and transaction data for real-time validation to determine if the wine product is counterfeit or not.  
A unique identifier is assigned to each wine product and written into the NFC tag. Tag-attached wine products are then shipped from winemakers to different nodes along the supply chain. During the transportation process of the wine products along the supply chain, each involved node could interact with the NFC tags and add the aforementioned four categories of data into the NFC tags. In this way, the next node can check whether or not the wine products have already passed through the legitimate supply chain. If any inconsistency is found at any node, such wine products may be considered counterfeits and should be returned to the winemakers. However, once the wine product reached the post-purchase stage and circulated in any customer-to-customer market, its authenticity is no longer guaranteed, as anyone who has an NFC reader could interfere and clone the tags' data. Therefore, it is important to develop anti-counterfeiting and traceability systems that could work even when the data of the tag are cloned in the post-purchase supply chain,with the security attacks detecting and preventing any potential adversary state transition from taking place.