When developing peer-to-peer applications on distributed ledger technology (DLT), a crucial decision is the selection of a suitable DLT design (e.g., Ethereum), because it is hard to change the underlying DLT design post hoc. To facilitate the selection of suitable DLT designs, we review DLT characteristics and identify trade-offs between them. Furthermore, we assess how DLT designs account for these trade-offs and we develop archetypes for DLT designs that cater to specific requirements of applications on DLT. The main purpose of our article is to introduce scientific and practical audiences to the intricacies of DLT designs and to support development of viable applications on DLT.

Smart contracts are a promising means of formalizing and reliably enforcing agreements between entities using distributed ledger technology (DLT). Research has revealed that a significant number of smart contracts are subject to programming flaws, making them vulnerable to attacks and leading to detrimental effects, such as asset loss. Researchers and developers call for a thorough analysis of challenges to identify their causes and propose solutions. To respond to these calls, we conducted two literature reviews and diverse expert interviews and synthesized scattered knowledge on challenges and solutions. We identified 29 challenges (e.g., code visibility, code updateability, and encapsulation) and 60 solutions (e.g., gas limit specification, off-ledger computations, and shadowing). Moreover, we developed 20 software design patterns (SDPs) in collaboration with smart contract developers. The SDPs help developers adjust their programming habits and thus support them in their daily development practices. Our results provide actionable knowledge for smart contract developers to overcome the identified challenges and offer support for comparing smart contract integration concepts across three fundamentally different DLT protocols (i.e., Ethereum, EOSIO, and Hyperledger Fabric). Moreover, we support developers in becoming aware of peculiarities in smart contract development and the resulting benefits and drawbacks.

Since the emergence of blockchain in 2008, we see a kaleidoscopic variety of applications built on distributed ledger technology (DLT), including applications for financial services, healthcare, or the Internet of Things. Each application comes with specific requirements for DLT characteristics (e.g., high throughput, scalability). However, trade-offs between DLT characteristics restrict the development of a DLT design (e.g., Ethereum, IOTA) that fits all use cases' requirements. Separated DLT designs emerged, each specialized to suite dedicated application requirements. To enable the development of more powerful applications on DLT, such DLT islands must be bridged. However, knowledge of cross-chain technology (CCT) is scattered across scientific and practical sources. Therefore, we examine this diverse body of knowledge and provide comprehensive insights into CCT by synthesizing its underlying characteristics, evolving patterns, and use cases. Our findings resolve contradictions in the literature and provide avenues for future research in an emerging scientific field.

Distributed ledger technology (DLT), including blockchain, enables secure processing of transactions between untrustworthy parties in a decentralized system. However, DLT is available in different designs that exhibit diverse characteristics. Moreover, DLT characteristics have complementary and conflicting interdependencies. Hence, there will never be an ideal DLT design for all DLT use cases; instead, DLT implementations need to be configured to contextual requirements. Successful DLT configuration requires, however, a sound understanding of DLT characteristics and their interdependencies. In this manuscript, we review DLT characteristics and organize them into six groups. Furthermore, we condense interdependencies of DLT characteristics into trade-offs that should be considered for successful deployment of DLT. Finally, we consolidate our findings into DLT archetypes for common design objectives, such as security, usability, or performance. Our work makes extant DLT research more transparent and fosters understanding of interdependencies and trade-offs between DLT characteristics.

Pollution-monitoring systems (PMSs) are used worldwide to sense environmental changes, such as air quality conditions or temperature increases, and to monitor compliance with regulations. However, organizations manage the environmental data collected by such PMSs in a centralized manner, which is why recorded environmental data are vulnerable to manipulation. Moreover, the analysis of pollution data often lacks transparency to outsiders, which may lead to wrong decisions regarding environmental regulations. To address these challenges, we propose a software design for PMSs based on distributed ledger technology (DLT) and the long-range (LoRa) protocol for flexible, transparent, and energy-efficient environment monitoring and data management. To design the PMS, we conducted a comprehensive requirements analysis for PMSs. We benchmarked different consensus mechanisms (e.g., BFT-SMaRt and Raft) and digital signature schemes (e.g., ECDSA and EdDSA) to adequately design the PMS and fulfill the identified requirements. On this basis, we designed and implemented a prototype PMS and evaluated it in the field. The evaluation shows the effectiveness of DLT-based PMSs that include portable low-energy sensor nodes and demonstrates the applicability of the proposed software design for PMSs in contexts other than air pollution.