arXiv subjects

Fabian Stiehle

Publications and source records attributed to Fabian Stiehle.

9 recordsLinked to original sources

arXiv2026

An Architecture for Decentralised Deployment and Operation of Blockchain Applications

Blockchains and distributed ledger technologies allow the operation of manifold decentralised applications (dApps). Such applications are based on smart contracts, a programmable abstraction that is executed in a decentralised manner. To ensure the correctness of smart contracts, blockchain application developers rely on DevOps practices such as automated testing and continuous integration and deployment. However, such infrastructure is often controlled by single entities. For larger blockchain applications, this issue is resolved by relying on concepts of Decentralised Autonomous Organisations (DAOs), which allow proposals to be autonomously executed once they reach a pre-defined quorum. Such a governance architecture is complex and requires integration with existing patterns for contract discovery and upgradeability. In this paper we integrate these concepts considering DevOps best-practices into a novel architecture that remains agnostic to different governance and upgrade implementations. We extend the known registry pattern to support deterministic deployments and present a decentralised deployment framework, including integration and deployment pipelines, user-interfaces, and version control integration. In our approach, each party implements and verifies their own tests before engaging in the use of a (newly deployed) smart contract. We provide a reference implementation, available as open-source, and evaluate the proposal thoroughly. Our architecture can serve as a reference for future integrations, while our open-source framework is aimed at reducing the complexity of adopting such a process in practice.

cs.SE↗

arXiv2026

Designing Value-Based Platforms: Architectural Strategies Derived from the Digital Markets Act

The digital markets act (DMA) regulates very large digital platforms like Meta's Facebook or Apple's iOS with the goal to promote fairness, contestability (of market power) and user choice. From a system design or broader technical perspective, the implications of the DMA have not been studied so far. Using systematic methods from qualitative coding and thematic analysis, we investigate the DMA from a technical perspective and derive eight high-level design strategies that serve as fundamental approaches towards value-based architectural goals like 'fair practice', or 'user choice' (as envisioned by the DMA). We investigate how compliance with the DMA has been achieved and derive 15 tactics that we map to our strategies. While the DMA obligations challenge existing platform designs, they also create new opportunities for designing services within these huge ecosystems. We, thus, discuss our strategies in light of both. We see this work as a first step towards filling this pressing gap in the architecture of platform ecosystems, i.e., how to incorporate abstract human values in architecture design.

cs.SE↗

arXiv2025

On LLM-Assisted Generation of Smart Contracts from Business Processes

Large language models (LLMs) have changed the reality of how software is produced. Within the wider software engineering community, among many other purposes, they are explored for code generation use cases from different types of input. In this work, we present an exploratory study to investigate the use of LLMs for generating smart contract code from business process descriptions, an idea that has emerged in recent literature to overcome the limitations of traditional rule-based code generation approaches. However, current LLM-based work evaluates generated code on small samples, relying on manual inspection, or testing whether code compiles but ignoring correct execution. With this work, we introduce an automated evaluation framework and provide empirical data from larger data sets of process models. We test LLMs of different types and sizes in their capabilities of achieving important properties of process execution, including enforcing process flow, resource allocation, and data-based conditions. Our results show that LLM performance falls short of the perfect reliability required for smart contract development. We suggest future work to explore responsible LLM integrations in existing tools for code generation to ensure more reliable output. Our benchmarking framework can serve as a foundation for developing and evaluating such integrations.

cs.SE↗

arXiv2025

Process Channels: A New Layer for Process Enactment Based on Blockchain State Channels

For the enactment of inter-organizational business processes, blockchain can guarantee the enforcement of process models and the integrity of execution traces. However, existing solutions come with downsides regarding throughput scalability, latency, and suboptimal tradeoffs between confidentiality and transparency. To address these issues, we propose to change the foundation of blockchain-based business process execution: from on-chain smart contracts to state channels, an overlay network on top of a blockchain. State channels allow conducting most transactions off-chain while mostly retaining the core security properties offered by blockchain. Our proposal, process channels, is a model-driven approach to enacting processes on state channels, with the aim to retain the desired blockchain properties while reducing the on-chain footprint as much as possible. We here focus on the principled approach of state channels as a platform, to enable manifold future optimizations in various directions, like latency and confidentiality. We implement our approach prototypical and evaluate it both qualitatively (w.r.t. assumptions and guarantees) and quantitatively (w.r.t. correctness and gas cost). In short, while the initial deployment effort is higher with state channels, it typically pays off after a few process instances; and as long as the new assumptions hold, so do the guarantees.

cs.CR↗

arXiv2024

The Cost of Executing Business Processes on Next-Generation Blockchains: The Case of Algorand

Process (or workflow) execution on blockchain suffers from limited scalability; specifically, costs in the form of transactions fees are a major limitation for employing traditional public blockchain platforms in practice. Research, so far, has mainly focused on exploring first (Bitcoin) and second-generation (e.g., Ethereum) blockchains for business process enactment. However, since then, novel blockchain systems have been introduced - aimed at tackling many of the problems of previous-generation blockchains. We study such a system, Algorand, from a process execution perspective. Algorand promises low transaction fees and fast finality. However, Algorand's cost structure differs greatly from previous generation blockchains, rendering earlier cost models for blockchain-based process execution non-applicable. We discuss and contrast Algorand's novel cost structure with Ethereum's well-known cost model. To study the impact for process execution, we present a compiler for BPMN Choreographies, with an intermediary layer, which can support multi-platform output, and provide a translation to TEAL contracts, the smart contract language of Algorand. We compare the cost of executing processes on Algorand to previous work as well as traditional cloud computing. In short: they allow vast cost benefits. However, we note a multitude of future research challenges that remain in investigating and comparing such results.

cs.SE↗

arXiv2024

LLMs for Science: Usage for Code Generation and Data Analysis

Large language models (LLMs) have been touted to enable increased productivity in many areas of today's work life. Scientific research as an area of work is no exception: the potential of LLM-based tools to assist in the daily work of scientists has become a highly discussed topic across disciplines. However, we are only at the very onset of this subject of study. It is still unclear how the potential of LLMs will materialise in research practice. With this study, we give first empirical evidence on the use of LLMs in the research process. We have investigated a set of use cases for LLM-based tools in scientific research, and conducted a first study to assess to which degree current tools are helpful. In this paper we report specifically on use cases related to software engineering, such as generating application code and developing scripts for data analytics. While we studied seemingly simple use cases, results across tools differ significantly. Our results highlight the promise of LLM-based tools in general, yet we also observe various issues, particularly regarding the integrity of the output these tools provide.

cs.SE↗

arXiv2024

Automatic Resource Allocation in Business Processes: A Systematic Literature Survey

For delivering products or services to their clients, organizations execute manifold business processes. During such execution, upcoming process tasks need to be allocated to internal resources. Resource allocation is a complex decision-making problem with high impact on the effectiveness and efficiency of processes. A wide range of approaches was developed to support research allocation automatically. This systematic literature survey provides an overview of approaches and categorizes them regarding their resource allocation goals and capabilities, their use of models and data, their algorithmic solutions, and their maturity. Rule-based approaches were identified as dominant, but heuristics and learning approaches also play a relevant role.

cs.SE↗

arXiv2022

Blockchain for Business Process Enactment: A Taxonomy and Systematic Literature Review

Blockchain has been proposed to facilitate the enactment of interorganisational business processes. For such processes, blockchain can guarantee the enforcement of rules and the integrity of execution traces - without the need for a centralised trusted party. However, the enactment of interorganisational processes pose manifold challenges. In this work, we ask what answers the research field offers in response to those challenges. To do so, we conduct a systematic literature review (SLR). As our guiding question, we investigate the guarantees and capabilities of blockchain-based enactment approaches. Based on resulting empirical evidence, we develop a taxonomy for blockchain-based enactment. We find that a wide range of approaches support traceability and correctness; however, research focusing on flexibility and scalability remains nascent. For all challenges, we point towards future research opportunities.

cs.SE↗

arXiv2021

Modeling the Block Verification Time of Zcash

An important aspect of the propagation delay in blockchain networks is the block verification time, which is also responsible for the so-called verifier's dilemma. Models for the block verification time can help to understand and improve the verification process. Moreover, modeling the verification time is necessary for blockchain network simulations. In this paper, we present JOIST, a new model for the block verification time of Zcash. We identify computationally complex operations in the verification process of Zcash, and derive our model based on characteristic transaction features. We evaluate JOIST and show that the model is consistently more accurate than existing models, which consider the block size only.

cs.CR↗