External Data Monitoring Using Oracles in Blockchain-Based Process Execution

• Published in: Business Process Management: Blockchain and Robotic Process Automation Forum Vol. 393; pp. 67 - 81
• Main Authors: Ladleif, Jan, Weber, Ingo, Weske, Mathias
• Format: Book Chapter
• Language: English
• Published: Switzerland Springer International Publishing AG 2020; Springer International Publishing
• Series: Lecture Notes in Business Information Processing
• Subjects: Data monitoring; Oracle architectures; Smart contracts
• ISBN: 9783030587789; 3030587789
• ISSN: 1865-1348; 1865-1356
• DOI: 10.1007/978-3-030-58779-6_5

In blockchain-based process execution, operational aspects of business processes are encoded in smart contracts on blockchains, enabling powerful auditing and compliance capabilities due to the platforms’ trust and integrity guarantees. However, smart contracts are subject to the blockchain’s conceptual limitations, which particularly restrict the real-time integration of external data. This potentially leads to non-compliant runtime behavior of process instances when data updates are missed and conditional constraints are wrongly evaluated. In this paper, we analyze the semantics of established external data interaction patterns in business processes with regards to their support on blockchain platforms. We extend and propose various oracle-based implementation strategies to alleviate conceptual issues independent of the concrete blockchain used, and discuss their properties and merits.