Implementation of Smart Contracts Using Hybrid Architectures with On- and Off-Blockchain Components

Recently, decentralised (on-blockchain) platforms have emerged to complement centralised (off-blockchain) platforms for the implementation of automated, digital (smart) contracts. However, neither alternative can individually satisfy the requirements of a large class of applications. On-blockchain platforms suffer from scalability, performance, transaction costs and other limitations. Off-blockchain platforms are afflicted by drawbacks due to their dependence on single trusted third parties. We argue that in several application areas, hybrid platforms composed from the integration of on- and off-blockchain platforms are more able to support smart contracts that deliver the desired quality of service (QoS). Hybrid architectures are largely unexplored. To help cover the gap, in this paper we discuss the implementation of smart contracts on hybrid architectures. As a proof of concept, we show how a smart contract can be split and executed partially on an off-blockchain contract compliance checker and partially on the Rinkeby Ethereum network. To test the solution, we expose it to sequences of contractual operations generated mechanically by a contract validator tool.Comment: 12 pages, 7 figure

Foundations of B2B electronic contracting

Nowadays, flexible electronic cooperation paradigms are required for core business processes to meet the speed and flexibility requirements dictated by fast-changing markets. These paradigms should include the functionality to establish the formal business relationship required by the importance of these core processes. The business relationship should be established in an automated, electronic way in order to match the speed and flexibility requirements mentioned above. As such, it should considerably improve on the ineffectiveness and inefficiency of traditional contracting in this context. The result of the establishment should be a detailed electronic contract that contains a complete specification of the intended cooperation between organizations. Electronic contracts should contain a precise and unambiguous specification of the collaboration at both the conceptual and technological level. Existing commercial software solutions for business-to-business contracting provide low level of automation and concentrate solely on the automated management of the contract enactment. However, in the modern, dynamic, business settings, an econtracting system has to support high automation of the e-contract establishment, enactment, and management. In the thesis, the business, legal, and technological requirements for the development of a highly automated e-contracting system are investigated. Models that satisfy these requirements and that can be used as a foundation for the implementation of an electronic contracting system are defined. First, the thesis presents the business benefits introduced to companies by highly automated electronic contracting. Next, a data and process analysis of electronic contracting is presented. The specification of electronic contracts and the required process support for electronic contract establishment and enactment are investigated. The business benefits and data and process models defined in the thesis are validated on the basis of two business cases from on-line advertising, namely the cases of online advertising in "De Telegraaf" and "Google". Finally, the thesis presents a specification of the functionalities that must be provided by an e-contracting system. A conceptual reference architecture that can be used as a starting point in the design and implementation of an electronic contracting system is defined. The work in the thesis is conducted on the intersection of the scientific areas of conceptual information and process modeling and specification on the one hand and distributed information system architecture modeling on the other hand

Monitoring multi-party contracts for E-business

"Monitoring multi-party contracts for E-business" investigates the issues involved in the performance of econtract monitoring of business automations in business to business e-commerce environment. A pro-active monitoring contract model and monitoring mechanism have been designed and developed. A new architecture and framework is proposed for pro-active monitorable contracts. This pro-active monitoring contract model is supported by a prototyp

Monitoring Multi-Party Contracts for E-Business.

"Monitoring Multi-party Contracts for E-business" investigates the issues involved in the performance of econtract monitoring of business automations in business to business e-commerce environment. A pro-active monitoring contract model and monitoring mechanism have been designed and developed. A new architecture and framework is proposed for pro-active monitorable contracts. This pro-active monitoring contract model is supported by a prototype

Contract specification for compliance checking of business interactions

PhD ThesisIn the business world, contracts are used to regulate business interactions between trading parties. When business transactions are conducted over an electronic channel, electronic forms of contracts are needed; and because of the additional capabilities of an electronic means, their function can be extended to include compliance checking for the interactions of the parties, and enforcement of contractual clauses when needed. A contract is assumed to be a document that stipulates a list of clauses stating rights, obligations and prohibitions, and their associated constraints, that business partners are expected to honour. Compliance checking is taken to mean checking if business operations executed by business partners match with their rights, obligations and prohibitions as stipulated in the contract. We intend enforcement as making sure that business operations match the rights, obligations, and prohibitions of the parties, possibly compensating for deviations from expected behaviour. In traditional business interactions, compliance checking and enforcement are carried out man- ually. With electronic business interactions, such tasks can ideally be automated. This requires a model for the process of checking contract compliance, and an electronic language for the speci ca- tion of the actual contract. The rst main contribution of this thesis is such a model. The EROP model (from Events, Rights, Obligations and Prohibitions), composed of an ontology and an architecture, observes the interactions between the business partners, forms an interpretation of their outcome from a neutral perspective and checks their contractual compliance by matching executed operations with their sets of rights, obligations, and prohibitions, and reacting accordingly to them. Implementations of the EROP ontology and of an experimental prototype of the architecture are also presented. The second main contribution of this thesis is the EROP language, designed to specify contractual compliance, and to regulate execution of business operations through the manipulation of the sets of rights, obligations and prohibitions of the business partners. The EROP language is rule-based and event-driven, and, in a similar fashion to contracts in natural language, contractual clauses are expressed as business rules, conditional statements associating events and conditions to lists of actions altering the rights, obligations and prohibitions of the participants. The practicality of the approach taken with the EROP language is evaluated presenting a larger, complete scenario and a number of smaller ones taken from comparable work. Notes on the translation of the EROP language to one on a lower level of abstraction that relies on the implementation of the EROP ontology are also presented. The Appendix presents a formal grammar for the language.UK EPSRC e-Science Pilot Project: "GOLD (Grid-based Information Models to Support the Rapid Innovation of High Value Added Chemicals)