**3. Enactment, Collaboration, and e-Governance**

Human-to-human business enactments are governed by enforceable contracts either in the form of an oral, or written agreement. Contract documents [22] uniquely identify the contracting parties, the offered services, or goods, a corresponding compensation, as well as further constraints such as delivery dates, quality goals, penalties, and means of arbitration [23]. Still, a highly-automated and machine-driven ecosystem requires a digital equivalent that is accessible to and usable by all stakeholders. Moreover, traditional solely human-focused contracts are often under-specified and thus, not suitable for M2X enactments [23]. "Most importantly, traditional contracts do not provide sufficient details about the actual transaction process, and consequently, frictions between the contracting parties are very likely, e.g., one party assumes a specific product certificate before delivering a partial compensation, and the other party assumes the opposite" [23].

Electronic smart contracts [24,25] address the listed issues by enabling and governing business transactions using a computerized transaction protocol such as a blockchain. Blockchain technology [26] ensures a trustworthy, tamper-resistant, P2P transaction processing, and enables a distributed, often decentralized, transparent way for communication. More generally, a blockchain is a distributed ledger that enables users to send data, process it, and verify it without the need for a central entity [26]. In addition, smart-contract blockchain technology comprises computer programs for the consistent execution by a network of mutually distrusting nodes where no arbitration of a trusted authority exists. As a result, allowing for fact tracking, non-repudiation, auditability, and tamper-resistant storage of information in a distributed multi-stakeholder setting.

On the one hand, the running case of Section 2.1 only presents a small fraction of potential applications and use cases of the M2X Economy. On the other hand, the running case already contains several examples of different M2X interactions, transactions, and collaborations, i.e., TaaS, road space negotiations, toll gate payments, BEV charging, traffic light information dissemination, and smart parking. The enactments of the listed examples follow a similar process structure, thus allowing for an abstraction towards a general lifecycle of the M2X Economy. Consequently, we stipulate that all M2X-related interactions, transactions, collaborations, and further enactments can be governed and represented using a blockchain-based smart contract.

In the following, Section 3.1 details a conceptual lifecycle for M2X business enactments and collaborations using electronic smart contracts. Afterward, Section 3.2 outlines corresponding distributed e-governance mechanisms.
