This project aim to define a framework to establish peer-to-peer trading of physical asset ownership through ethereum blockchain.

The framewrok have been structured into three distinct macro phases: Tokenization, Trading and Redemption.

First and last macro phases, tokenization and redemption, respectively, are in charge of the digital twin management, where the middle macro phase, the trading phase, is a pure peer-to-peer token trading that runs exclusively on digital.

The main advantage of this solution is provided by the position of the trading macro-phase, which is nasted between the tokenization and the redemption macro-phase so as to allow the trading phase of the tokenized physical asset to work without the involvement of any third party. This is enabled by the fact that the traded token is all along binded with his respondent physical asset through reputation mechanism and, moreover, this binding feature is transparent, and trading phase is not anyhow affected by the first or the third macro phase.

Four roles have been used to define all possible types of user that use this framework:

1. Smart contract who define all the roules of allowed interactions and track the changes
2. Vendor who own the physical asset and want to tokenize it with the ultimate intent to sell it by leveraging on digital market benefits.
3. Trader who wants to buy the token to obtain the physical asset or make a profit by reselling the digital token to another trader.
4. Warehouse Tokenizator who wants to profit by providing the digital twin assurance service by leveraging his reputation.

The digital twins assurance service, provided by Warehouse Tokenizator, consists of two mandatory subservices:

1. Issue tokens that respect the physical characteristics of the asset
2. The custodial service so that traders are assured that the responded physical asset exists as described on the digital token and is available for redemption.

In this way, the token acts as a proof of integrity and availability, while the reputation of the warehouse tokenization represents the stake as a guarantee.

Within the entire custodial service agreement, the warehouse tokenizator is responsible for maintaining the asset as it was received; therefore, since no changes could occur in the physical asset during the custodial service, the digital twin is implicitly obtained due to the reputation of the warehouse tokenizator as stake. Thus, in case changes occur, the service fails, and thus warehouse tokenizator reputation will be affected.

This aspect is part of the risk evaluation when a service quote is offered to the vendor and when the vendor evaluates the proposals received to the warehouse tokenizator service.

Since both tokenization and redemption phases are reputation based, users that want to interact with this framework as vendor or warehouse tokenizator must first define their roule by registering their relevant informations into the blockchain by using the rules defined on the smart contract. These information are public and useful for recognizing the user and his reputation that is initialized as zero at the time of registration. They also include the geographic location that will be used to estimate the logistic cost and an off-chain contact address, such as e-mail, that will be used to deliver private messages that are not required to be stored on the blockchain.