*3.1. Digital Contract Lifecycle Management*

Based on [23], Norta presents a conceptual smart contract-based lifecycle as illustrated in Figure 2.

**Figure 2.** Conceptual lifecycle for M2X business enactments–Based on [1,23].

The lifecycle is divided into seven stages: (*<sup>i</sup>*.) preparation, (*ii*.) negotiation, (*iii*.) governance distribution (*iv*.) preparation of collaboration enactment (*<sup>v</sup>*.) collaboration enactment (*vi*.) rollback, and (*vii*.) termination stage.

The preparatory stage is initiated by selecting a pre-configured template from a distributed service hub. The distributed service hub hosts contract templates that match different M2X use-cases and outlines the corresponding contractual process flow. Following the running case, a template for TaaS is selected and populated with information about the involved entities, such as identifiers and wallet addresses. Moreover, TaaS-specific conditions are defined, e.g., departure location, final destination, the required vehicle size, and the departure/arrival time. Subsequently, the TaaS contract request is negotiated with potential TaaS service providers, i.e., autonomous vehicles. The negotiated-contract conditions primarily depend on information such as the travel distance and energy consumption of the vehicle as well as the number of transported individuals.

The negotiation stage concludes either with an agreement—resulting in a contract signed by both parties to express their approval—or a contract rollback if no agreemen<sup>t</sup> is reached. In our case, Alice and the vehicle serving the direct route between A and B agree upon a set of rights and obligations. Subsequently, a smart contract is established and serves as a distributed governance infrastructure (DGI) coordinating agen<sup>t</sup> (also see Figure 3). Finally, the e-governance distribution commences, Alice and the vehicle each receive local contract copies containing the respective obligations and rights of each party resulting from the previous negotiations [23]. The vehicle's and Alice's obligations are observed by monitors and are assigned so-called business-network model agents (BNMA) that connect to IoT-sensors such as the vehicle's GPS-sensor [23].

The required process endpoints, e.g., for paymen<sup>t</sup> processing as Alice pays using the cryptocurrency of her choice, are prepared and provided as part of the contract enactment preparation. "Once the e-governance infrastructure is set up, technically realizing the behavior in the local copies of the contracts requires concrete local electronic services. After picking these services, follows the creation of communication endpoints so that the services of the partners are able to communicate with each other. The final step of the preparation is a liveness check of the channel-connected services" [23].

Next, the contract execution stage is triggered, and the vehicle picks up Alice at location A. The TaaS contract enactment terminates, or expires once Alice arrives at Point B. Alternatively, the contract is prematurely terminated, e.g., failing to transport Alice to Point B, or violating agreed upon time restrictions, might result in an immediate rollback of the TaaS contract, or invokes a mediation process that is supervised by a conflict-resolution escrow service that is not depicted in Figure 2. Note that the enactment of the TaaS running case subsumes further M2X enactments that occur throughout the TaaS service provision, e.g., the vehicle pays a minor fee at the toll gate to use the faster toll road. The toll road paymen<sup>t</sup> is part of the costs to transport Alice from Point A to B and is thus, included in her fare.
