## 3 Related Work  
Various techniques have been proposed to enhance the tracking and tracing capabilities of parts inside the supply chain. In the food industry, the introduction of IoT technologies is exploited to enhance food safety and traceability: QR code technology is proposed in ref. [26] to trace the logistic steps of vegetables; RFID anchors are instead proposed to enhance the traceability of the fish supply chain in ref. [27]. An RFID-enabled supply chain is also explored in ref. [28], where a theoretical model is proposed and evaluated on an aerospace manufacturing process. Those technologies provide promising results regarding the tracking and traceability requirements of physical parts but have a common weakness regarding the authenticity of the hyperlink: both technologies suffer from a clone vulnerability that makes the introduction of counterfeit parts in the supply chain possible. RFID tags support hash operations, symmetric encryption, or Physically Unclonable Functions (PUFs) [29]. This is the case of the secure protocol Cipurse [30], which uses symmetric cryptography (often Advanced Encryption Standard, AES [31]) to authenticate a tag. Even if this protocol can be applied to NFC [32], it focuses on the secure use of symmetric cryptography inside the tag to keep the tag's secret protected from the majority of attacks. However, the authenticator needs complete or partial knowledge of this secret to perform the authentication, which gives the authenticator the possibility of creating falsifications. The secure management of this secret is a critical point of the symmetric cryptography, which is out of the scope of Cipurse. There are many works in the state-of-the-art proposing solutions to this problem. In accordance with the survey in ref. [14], almost all the proposed solutions require relying on a centralized entity to identify the clones. This would allow this entity to record fake data about an authentication (tampering attack) or to clone a tag (spoofing attack). The only author in this survey that supports a decentralized solution is [PERSON] [15]. This system uses read/write tags without hardware protection, i.e., everyone can read/write. Every tag contains the ID of the product and the cryptographically protected path of this ID. This solution cannot protect against cloning but proposes a method to detect it. In this method, all partners in the supply chain check between them that the same ID is not used in the two partners' stores. This solution is difficult to apply because it requires not only the cooperation of all the partners in the supply chain but also in the market, e.g., a counterfeit with a cloned ID could be sold to an assembler, and the partner would never detect it if they do not compare their database with the distributor from a different supply chain line that has the original product. Also, another problem is that even if the path in the tag cannot be modified, it can be restored to an old version. So, when a part is in a non-auditable state (i.e., in final user control or discontinued), the distributor can clone its ID and its old path information, include it in the tag of a counterfeit, and sell it like a new and legitimate part. Apart from that, another more recent work from [PERSON] et al. [33] presents a solution with a self-made blockchain to protect product-related information. In this way, the asset's path information cannot be modified. When a stakeholder receives an asset, it reads from the tag the secret \"RFID address\" and uses it to identify in the blockchain the product-related information. This secret is also used to send valid transactions to the blockchain and includes more product-related information. The problem with the solution is that there are not any mechanisms used to avoid or detect clones of the RFID tags. Therefore, any stakeholder or an attacker who could scan the part can clone the tag and sell a counterfeit. [PERSON] et al. [17] proposes a mechanism where only authorized entities can identify the tags.