Negotiations of different kinds are used to trade goods and services. Within these, the creation of a signed agreement or contract that is binding for the agreeing parties helps also the gathering of evidence that can be used in case of disputes and for adjudication. Traditionally, contracts are established on paper agreements that are signed by all the involved parties and by a law enforcement entity that ensure its legality in a court of law. These contracts have evolved with the introduction of Information Technology (IT) where the negotiation of goods and services is mainly virtual and/or automatized. The consistency and processing time of the computers allow for negotiations to be more efficient than ever. 

Digitalized negotiations allow for auctioning systems providing a mechanism to efficiently match demand and supply in the exchange of goods and services. Such suctioning systems allow multiple users to iteratively or non-iteratively compete against one another to achieve allocative efficiency. Lately, digitalized auctions are implemented using Blockchain systems with the use of Smart Contracts to archieve decentralization. These are implemented as a digital script that may encode any set of rules written as code, with the validity of the code being enforced by the Blockchain's consensus mechanism. These Smart Contracts computations however tend to be expensive when executed and limited by the blocksize.  

This thesis studies the creation of digitized negotiation protocols and contract definition following the needs of traditional trading and auctioning systems. We investigate the use of Ricardian Contracts for flexible representation of rights and obligations of entities in the context of circular economy in both single and multi-attribute auctions. We analyze the implication of digitized agreements in the context of data sharing. Furthermore, we analyze how usage control policies can be represented into Ricardian Contracts in the context of intellectual property protection, compliance with regulations, and digital rights management.Finally, we analyze the properties that a system that supports the mentioned models should have and how to implement it in the context of distributed auctioning systems by contrasting available state-of-the-art. 

The main contributions of the thesis are: (1) The creation of a multi-attribute auctioning protocol for the circular economy which implements Ricardian Contracts for the representation of rights and obligations. (2) A method to negotiate obligations and access provisions with multi-level Ricardian contracts, and automatically enforce those provisions with access control. (3) A state-of-art analysis on distributed and decentralized auctioning systems where the key properties of auctioning systems are identified and are evaluated against the current implementations.

Digitalization represents a fundamental transformation in how we process information and conduct negotiations. It refines existing workflows, improves efficiency, enhances customer experience, and allows for better collaboration within ecosystems, promoting industrial sustainability and circularity.

The control and storage of digitalized systems are traditionally centralized, requiring trust in a third party in charge of processing data associated with negotiations, determining the outcome, and storing it. However, this centralized entity may not be trustworthy, as it may favor a particular party or misuse the information it processes. To meet this, there is a trend towards decentralized models. Recently, blockchain systems and Distributed Hash Tables (DHT) have gained popularity for decentralized transaction processing, and storage. While these systems offer many advantages for creating decentralized interactions and storing data, they need extensions to support negotiations as they are typically designed for executing single transactions rather than iteratively negotiating in time-constrained settings. Furthermore, decentralized data storage systems often do not support bidirectional relationships, capturing the need for event tracing in supply chains.

The scope of this thesis is the digitalization of negotiation mechanisms and data storage systems in the context of the circular economy. The early part focuses on designing price-only and multi-attribute open-cry auctioning systems and automating digitalized negotiations. This includes identifying key properties and features in open-cry auctioning systems and contract establishment procedures, consisting of machine and human-readable agreements. Additionally, the work on digitalized contract establishment extends to the representation of rights and obligations in access control. Then, various decentralized approaches are analyzed for transitioning open-cry auctions to decentralized models. From this, a system design for a decentralized auction system based on blockchain is presented, along with an implementation using Hyperledger Fabric. The latter part of the paper explores how decentralized systems can effectively represent and query highly interconnected data. It presents a solution using the Interplanetary File System (IPFS) to address these challenges. Furthermore, the implementation is extended to the realm of sustainability by examining Digital Product Passports.

The results of the work presented in this thesis show the potential of digitalized negotiations for the agreement of rights and obligations in access control and open-cry auctions and the limitations of their implementation using blockchain technologies. Lastly, it demonstrates the use of IPFS for storing and linking data and its ability to enable traceability and accountability throughout product lifecycles.