DeMaTO: An Ontology for Modeling Transactional Behavior in Decentralized Marketplaces

Blockchains are distributed ledger platforms that were originally envisioned for implementing digital assets and cryptocurrencies such as BITCOIN. Mainstream blockchain platforms such as Ethereumand Hyperledgersupport both "native" transactional behavior i.e., transferring cryptocurrency assets, as well as, other types of transactional behavior relevant to an emerging class of applications called decentralized applications or DApps. However, "non-native" transactional behavior is achieved in terms of user-defined programs, commonly referred to as smart contracts. Unfortunately, smart contracts have several known limitations, including the burden on both implementor and contract consumers, being prone to financially-costly errors, higher cost of execution, and overall difficulty with concurrency optimization. Further, there is a lack of standardization with respect to implementation. Consequently, this contributes to the difficulty of enabling interoperability across blockchains. In this paper, we propose an ontology DeMaTO for modeling transactional behavior on blockchains as a foundation for extending blockchain transaction primitives. As an application context, we focus on marketplace transactions because marketplaces are one of the most popular categories of DApps, i.e., decentralized marketplaces. This modeling of transactional behavior complements the modeling supported by existing ontologies that focus on the infrastructure layer. We illustrate how DeMaTO can be used in blockchain transaction modeling and its value with respect to blockchain queryability and transaction validation.