Figure 4
The sequence diagram displays five actors at the top from left to right: “C E M S and S M Oracles” with a thermometer and scale icon, “Cement Manufacturer” with a cement bag icon, “Regulatory Authority” with a classical building icon, “Sustainability Certification S C” with a document and gear icon, and “I P F S Slash Decentralised storage” with a server and data icon. Vertical dashed lines descend from each actor. A legend box positioned on the right displays “Legend,” with “Events” indicated by a red dashed line segment with red and blue dots, “On-Chain” indicated by a black solid horizontal arrow, and “Off-Chain” indicated by a blue solid horizontal arrow. From top to bottom, the interactions proceed as follows: An “Off-Chain” arrow points leftward from “Regulatory Authority” to “Cement Manufacturer” labeled “Request registration.” An “Off-Chain” arrow points left from “Regulatory Authority” to “Cement Manufacturer,” labeled “Provide registration requirements.” An “On-Chain” arrow points right from “Regulatory Authority” to “Sustainability Certification S C,” labeled “Deploy Sustainability Certification S C.” An “On-Chain” arrow points right from “Cement Manufacturer” to “I P F S Slash Decentralised storage” and is labeled “Upload registration information to I P F S, get I P F S hash.” An “On-Chain” arrow points right from “Cement Manufacturer” to “Sustainability Certification S C,” labeled “Upload required registration info to registration S C (E A, I P F S hash, other manufacturer info).” An “Events” arrow extends rightward from “Cement Manufacturer” to “I P F S Slash Decentralised storage.” A blue dot is placed on “Sustainability Certification S C,” labeled “Registration requested (Event).” An “On-Chain” arrow points right from “Regulatory Authority” to “I P F S Slash Decentralised storage” and is labeled “Review registration information.” An “On-Chain” arrow points right from “Regulatory Authority” to “Sustainability Certification S C,” labeled “Approve registration, assign registration status.” An “Off-Chain” arrow points right from “C E M S and S M Oracles” to “Regulatory Authority,” labeled “Install and check C E M S and S M.” An “Events” arrow extends rightward from “Cement Manufacturer” to “I P F S Slash Decentralised storage.” A blue dot is placed on “Sustainability Certification S C,” labeled “Registration complete (Event).”Sequence diagram illustrating the interactions of stakeholders with the SCs in the registration phase of the proposed framework. Source: Authors' own creation/work