Zero-knowledge virtual machine (zkVM) is a powerful infrastructure for proving the correctness of a program execution with a succinct proof, attracting significant interest from researchers, developers, and users. It has been widely used in applications such as blockchain rollups, privacy-preserving machine learning, and off-chain computation. As the field grows, a wide range of zkVMs have been proposed. However, they adopt different choices in instruction formats, trace layouts, and proving backends, which results in a highly heterogeneous design landscape and makes it difficult to understand the relations among these systems.To bridge this gap, we provide a comprehensive study of zkVMs that covers both their theoretical foundations and practical implementations. We decompose zkVMs into three layers: (1) the ISA layer, which defines instruction semantics and determines the structure of the execution trace, (2) the VM layer, which captures program execution and organizes constraints through modular circuit components, and (3) the proving layer, which converts execution traces into algebraic constraints and generates the final proofs. This decomposition allows us to isolate the role of each layer while also examining how they interact in real systems. To give readers a more direct understanding of how these design choices affect performance, scalability, and usability, we conduct a comprehensive experimental evaluation of representative zkVMs following this layered framework. Finally, we conclude the paper by summarizing the main observations from our analysis and outlining several potential directions for zkVM design and implementation.
Decentralized identity (DID) systems promise improved privacy, user control, and interoperability in regulated digital identity verification, including in banking contexts. However, existing DID implementations often introduce usability barriers that limit adoption, particularly for non-technical users navigating Know-Your-Customer (KYC) onboardingâa mandatory process requiring banks to verify customer identity to prevent fraud and financial crime. This poster presents a UX-centred, four-phase mixed-methods investigation comparing a high-fidelity DID-based onboarding prototype with a traditional Web2 (centralised, platform-owned) KYC flow. Results show that DID significantly reduced task completion time (178s vs. 665s), improved perceived usability (SUS: 93.4 vs. 71.3), and increased user trust (6.1 vs. 5.1 on a 7-point scale). At the same time, wallet setup, private-key management, and the absence of onboarding-phase recovery guidance remain critical sources of user anxiety. We contribute five user-centered design principles for DID-enabled financial onboarding and discuss implications for designers working at the intersection of Web3 (decentralised, blockchain-based systems), fintech, and regulated digital services.
Abstract Software development plays a central role in digital sustainability, yet developersâ role and engagement remains understudied. Here we analyse nearly a decade of developer discussions available on the code repository Github on Ethereum, a widely used open-source blockchain platform. Using topic modelling, with interpretation supported by large language models and a sustainability framework for software systems, we trace how economic, environmental, social, individual, and technical sustainability themes emerge and evolve over time. We find that sustainability awareness, particularly related to energy efficiency and cost, intensifies during key events such as the transition from proof-of-work to proof-of-stake consensus, which substantially reduced energy use. We identify influential contributors and thematic specialisation, providing a transferable framework for understanding sustainability in emerging developer communities. These findings highlight the role of developer discourse in shaping sustainable software ecosystems and integrating sustainability into open-source development.
Non-fungible tokens (NFTs) are unique digital tokens issued on a blockchain to represent the proof of ownership of (digital) items. Despite their impressive technological capabilities and millions of users, research and practice lack an understanding of the factors motivating NFT purchases. In this study, we employ a sequential mixed-method approach to reveal what drives users to purchase NFTs. We performed 65 in-depth interviews (Study 1) with individuals who purchased at least one NFT to explore the factors that influence their decisions. Building on these insights, we carry out two surveys: one with 265 individuals who have purchased NFTs (Study 2), and another with 272 individuals who have considered buying an NFT but have not done so (Study 3). Using a fuzzy-set qualitative comparative analysis, we reveal the combinations of influencing factors leading to NFT adoption in our sample. Building on self-determination theory, our aggregated findings emphasize the importance of intrinsic interest. We developed four propositions grounded in our data to guide future research. This study provides unique empirical insights into the adoption behaviour of NFTs as an emerging technology from a user perspective.
This study examined the role of visual design in Non-Fungible Tokens (NFTs) as a strategic component of value creation and inclusive participation within the decentralized creative economy. The research addressed the growing need to understand how visuals influence identity, accessibility, and community-driven economic engagement in digital platforms. The study was conducted using a qualitative interpretive approach, employing visual rhetorical analysis and digital ethnography. Ten top NFT collections on the OpenSea marketplace were analyzed based on their visual characteristics, creator inclusion, and community interaction. The visual elements were assessed through rhetorical lenses ethos, pathos, and logos, while participation was observed through social media metrics and community discourse. The findings indicated that accessible and culturally resonant visual designs enhanced user engagement and contributed to broader economic inclusion. Collections with visually open, emotionally engaging, and culturally inclusive features attracted stronger community involvement and sustained market relevance. In contrast, NFTs with elitist or exclusive visual narratives demonstrated more limited participation and accessibility. The study concluded that visual identity plays a central role in shaping the success of NFTs not only as aesthetic artifacts but as instruments of economic democratization. It was recommended that future research explore algorithmic visual production and long-term community dynamics across diverse cultural contexts. This research highlighted the potential of visual design to foster equity, representation, and sustainable value in the evolving digital economy.
The design of Web3 applications presents unique challenges due to their complex technical requirements. Despite the increasing spread of this technology, there is a notable lack of comprehensive, empirically grounded design guidelines for developing user-friendly Web3 interfaces. This study addresses this gap through a systematic three-phase approach: (1) developing initial guidelines from a literature review and industry sources (n = 31), (2) conducting evaluations using a 14-point framework based on the initial guidelines to test its effectiveness across diverse Web3 applications (n = 25), and (3) validating refined guidelines through expert evaluation sessions (n = 7). Expert evaluations highlighted the need for task-oriented rather than category-based organization of design principles. Based on these findings, we developed a structured framework organizing guidelines into four key task flows, each with three implementation levels. The framework emphasizes progressive disclosure of blockchain concepts, integrated user education, and clear state visualization. Our findings contribute to academic discussion and industry practice by providing empirically validated patterns for Web3 interface design. This study lays a foundation for creating more accessible and user-friendly decentralized applications, though future work should focus on longitudinal validation and adaptation to emerging technologies.
Frances Liddell, Ella Tallyn, Evan Morgan, Kar Balan ¡ 10 authors
In this work-in-progress, we present ORAgen, as âunfinished softwareâ, materialised through a demonstrative web application that enables participants to engage with a novel approach to media tokenisation â the ORA framework. By presenting ORAgen in âthink-aloudâ interviews with 17 professionals working in the creative and cultural industries, we explore potential values of media tokenisation in relation to existing challenges they face related to ownership, rights, and attribution. From our initial findings, we reflect specifically on the challenges of attribution and ongoing control of creative media, and examine how media tokenisation, and underpinning distributed ledger technologies can enable new approaches to designing attribution.
Xolminds is a web3 based self improvement platform that seeks to support people in reimagining their lives, recreating themselves and coping with mental health issues and challenges.
Chris Elsden, Evan Morgan, Ella Tallyn, Suzanne Black ¡ 8 authors
This paper presents the design, deployment and qualitative study of a large-scale, public, generative art exhibition, through which passers-by could create artworks, and mint a non-fungible-token (NFT). Following the month-long exhibition, during which 229 anonymous participants produced artworks, 69 non-transferable NFTs were minted, we surveyed (33) and interviewed (14) expert and novice participants about their experiences. We explored contemporary challenges of owning digital things, and the extent to which NFTs, and 'Web3' technologies offer meaningful forms of ownership. Our findings describe how the inability to trade this NFT, and its unique circumstances of acquisition, made it meaningful in ways that extended beyond its immediate (limited) utility and offered participants something through which to construct identity. Reflecting on the aspirations, contradictions, and misconceptions of forms of ownership enabled by NFTs, we conclude with proposals for renewed attention in HCI to the nature of digital possessions, and the potential for 'ownership design'.
Abstract Counterfeit artwork presents a significant risk to copyright holders and the economy. Without expertise in art, it is not straightforward to distinguish an artwork counterfeit from a genuine piece. This work designs and implements a reliable solution that enables users with nearâfield communicationâenabled Android smartphones to verify artwork authenticity by accessing its respective certificate of authenticity stored in the Ethereum blockchain. To represent a physical artwork, the artwork image and metadata are stored in an interâplanetary file system and minted as an ERC721 nonâfungible token to a smart contract deployed in Ethereum Rinkeby Testnet. The mobile app ArtProtect was developed to generate certificate of authenticity based on each nonâfungible token fetched through OpenSea Testnet API. Users access this information by scanning an nearâfield communication tag embedded into the artwork. The content of the tag is signed by the respective artwork's artist and responsible agent by using Ethereum signing with their Ethereum wallet accounts. Through testing and analysis, the implemented work is secure, tamperâevident, usable, flexible, and inexpensive to be applied to a realâworld scenario.
Open access
User Authentication and Security Systems
Innovative Human-Technology Interaction
Advanced Steganography and Watermarking Techniques
Through two experiments with volumetric and one experiment with edible Non-Fungible Tokens (NFTs) conducted between 2021 and 2022, we will discuss the limits of âassetizationâ and engagement with speculative future and value. Assetization is a process of claiming or generating âfutureâ value that creates various (not only economic) expectations and incentives. To capture the novel aesthetic expectations and experiences beyond assetization, we will focus on the edge cases, such as edible NFTs and also NFTs related to large volumetric (mesh) data. How can fringe NFTs mitigate some of the negative effects of commodification and market speculation? Our use cases show that a major barrier for assetization and tokenization of alternative and novel values, impacts, and goals are the closed data and software silos, but also the user-unfriendly interfaces for interacting with the blockchain infrastructure. Instead of creating new markets and media ecosystems that generate new sources of income for the creators, NFTS still transform cultural artifacts into speculative investments with detrimental effects.
Open access
Additive Manufacturing and 3D Printing Technologies
NFT marketplaces have witnessed exponential growth. The unique attributes of NFTs, encapsulated by the acronym CRAVED (concealable, removable, available, valuable, enjoyable, disposable), make them susceptible to multifaceted thefts. In response, we introduce "SafeNFT Mart," an NFT marketplace architecture devised to thwart counterfeiting and uphold both asset and ownership integrity. We leverage Zero Knowledge Proofs (ZKPs) for ownership verification and integrate a stringent punishment protocol to deter illicit activities. Our design draws from the design science research (DSR) approach. Expert interviews were conducted to fortify our findings, focusing on relevance, adaptability, and technological viability in tandem with real-world and strategic implications. An initial analytical model is provided to gauge the efficacy of our punitive mechanism. This research culminates with future work, outlining the further development and refinement of the proposed marketplace solution.
Open access
Physical Unclonable Functions (PUFs) and Hardware Security
Reporting on the Non-Fungible Token (NFT) ecosystem overwhelmingly focuses on the community that drove its growth and price volatility, gaining widespread media attention in 2021. This overlooks the communities developing novel creative practices on NFT platforms. Interviews with 16 creatives utilizing NFTs reveal a vast Art World: networks of distinct communities maturing into cooperative ecosystems with unique artistic subcultures, philosophies, and interactions. We observe unique qualities of these decentralized distribution platforms and identify patterns of activity comparable to those of traditional art worlds. We identify how aspects of these systems might subvert, or replicate, existing systems of power, value, and access. The impacts of policy and platform design on online creative communities in the NFT Art World carry valuable lessons for developers of digital interventions into the creative industry, exemplifying pertinent considerations for the future of creative labor and cooperation online.
The fervor for Non-Fungible Tokens (NFTs) attracted countless creators, leading to a Big Bang of digital assets driven by latent or explicit forms of inspiration, as in many creative processes. This work exploits Vision Transformers and graph-based modeling to delve into visual inspiration phenomena between NFTs over the years, i.e., the visual influence that can be detected whenever an NFT appears to be visually close to another that was published earlier in the market. Our goals include unveiling the main structural traits that shape visual inspiration networks, exploring the interrelation between visual inspiration and asset performances, investigating crypto influence on inspiration processes, and explaining the inspiration relationships among NFTs. Our findings unveil how the pervasiveness of inspiration led to a temporary saturation of the visual feature space, the impact of the dichotomy between inspiring and inspired NFTs on their financial performance, and an intrinsic self-regulatory mechanism between markets and inspiration waves. Our work can serve as a starting point for gaining a broader view of the evolution of Web3.
Part of the recent developments in Ubiquitous Music (ubimus) research involve the proposal of the Internet of Musical Stuff (IoMuSt) as an expansion and complement to the Internet of Musical Things (IoMusT). The transition from IoMusT to IoMuSt entails a critique of blockchain and non-fungible tokens (NFTs) as technologies for allotment, disciplination and regimentation of formerly open and freely accessible artistic web content. In brief, the replacement of the operative concepts constructed around âthingsâ with strategies based on âstuff â highlights the underlying interconnected processes and factors that impact interaction and usage, pointing to resources that become disposable and valueless within an objectified and monetized musical internet. This conceptual and methodological turn allows us to deal with distributed-creativity phenomena in marginalized spaces, highlighting the role of resources that are widely reproducible, fluid and ever-changing. In this paper, we address IoMuSt-based responses to issues such as the artificial production of scarcity associated with the application of NFTs. The selected musical examples showcase the meshwork of dynamic relationships that characterizes ubimus research. In particular, we focus on a comprovisation project involving VOIP visual communication through Skype, Meet and Zoom, a ubimus experience involving a Telegram chatbot and a set of musical experiments enabled by an online tool for remote live patching.
User Interaction for NFTs (Non-fungible Tokens) is gaining increasing attention. Although NFTs have been traditionally single-use and monolithic, recent applications aim to connect multimodal interaction with human behavior. This paper reviews the related technological approaches and business practices in NFT art. We highlight that multimodal interaction is a currently under-studied issue in mainstream NFT art, and conjecture that multimodal interaction is a crucial enabler for decentralization in the NFT community. We present a continuum theory and propose a framework combining a bottom-up approach with AI multimodal process. Through this framework, we put forward integrating human behavior data into generative NFT units, as "multimodal interactive NFT." Our work displays the possibilities of NFTs in the art world, beyond the traditional 2D and 3D static content.
In the age of machine learning, cryptocurrency mining, and seemingly infinite data storage capacity enabled by cloud computing, the environmental costs of ubiquitous computing in modern life are obscured by the sheer complexity of infrastructures and supply chains involved in even the simplest of digital transactions. How does computation contribute to the warming of the planet? As information technology (IT) capacity demands continue to trend upward, what are some of the ecological obstacles that must be overcome to accommodate an ever-expanding, carbon-hungry Cloud? How do these material impacts play out in everyday life, behind the scenes, where servers, fiber optic cables, and technicians facilitate cloud services? This case study draws on firsthand ethnographic research in data centersâÂÂsprawling libraries of computer servers that facilitate everything from email to commerceâÂÂto identify some of the far-reaching and tangled environmental impacts of computation and data-storage infrastructures. It surveys a range of empirical accounts of server technicians to illustrate on-the-ground examples of material and ecological factors that permeate everyday life in the Cloud. These examples include air conditioning and thermal management, water cycling, and the disposal of e-waste. By attending to the culture of workplace practice and the behaviors and training of technicians in data centers, this case study reveals that the Cloud is not fully automated, nor is it hyperrational; emotion, instinct, and human judgment are enlisted to keep servers running. This case study closes with a speculative vignette that scales up from various local impacts to a planetary framework, sketching some of the particular ways that computation contributes to climate change and the Anthropocene.
Dave Murray-Rust, Chris Elsden, Bettina Nissen, Ella Tallyn ¡ 6 authors
This paper presents an annotated portfolio of projects that seek to understand and communicate the social and societal implications of blockchains, distributed ledgers and smart contracts. These complex technologies rely on human and technical factors to deliver cryptocurrencies, shared computation and trustless protocols but have a secondary benefit in providing a moment to re-think many aspects of society, and imagine alternative possibilities. The projects use design and HCI methods to relate blockchains to a range of topics, including global supply chains, delivery infrastructure, smart grids, volunteering and charitable giving, through engaging publics, exploring ideas and speculating on possible futures. Based on an extensive annotated portfolio we draw out learning for the design of blockchain systems, broadening participation and surfacing questions around imaginaries, social implications and engagement with new technology. This paints a comprehensive picture of how HCI and design can shape understandings of the future of complex technologies.
The envisioned embracing of thriving knowledge societies is increasingly compromised by threatening perceptions of information overload, attention poverty, opportunity divides, and career fears. This paper traces the roots of these symptoms back to causes of information entropy and structural holes, invisible private and undiscoverable public knowledge which characterize the sad state of our current knowledge management and creation practices. As part of an ongoing design science research and prototyping project, the article's (neg)entropic perspectives complement a succession of prior multi-disciplinary publications. Looking forward, it proposes a novel decentralized generative knowledge management approach that prioritizes the capacity development of autonomous individual knowledge workers not at the expense of traditional organizational knowledge management systems but as a viable means to foster their fruitful co-evolution. The article, thus, informs relevant stakeholders about the current unsustainable status quo inhibiting knowledge workers; it presents viable remedial options (as a prerequisite for creating the respective future generative Knowledge Management (KM) reality) to afford a sustainable solution with the generative potential to evolve into a prospective general-purpose technology.
Open access
Personal Information Management and User Behavior
Innovative Human-Technology Interaction
Innovative Approaches in Technology and Social Development
In this position paper we discuss the methodological challenges associated with engaging citizens, publics and research participants in speculations around future socio-technical systems. We focus on distributed autonomous organizations and associated smart contracting and distributed ledger technologies as an example of such systems. Drawing on our prior work on Speculative Enactments, we highlight the potential value of speculative approaches to engaging people in the design of DAOs that (i) have clear consequentiality for participants, (ii) illustrate scenarios of the future mundane involving these technologies, and (iii) give opportunities for participants to co-construct speculations. We suggest these as provocative starting points to conducting future participatory and speculative design research on DAOs, and to promote discussion with workshop attendees.
This workshop aims to develop an agenda within the CHI community to address the emergence of blockchain, or distributed ledger technologies (DLTs). As blockchains emerge as a general purpose technology, with applications well beyond cryptocurrencies, DLTs present exciting challenges and opportunities for developing new ways for people and things to transact, collaborate, organize and identify themselves. Requiring interdisciplinary skills and thinking, the field of HCI is well placed to contribute to the research and development of this technology. This workshop will build a community for human-centred researchers and practitioners to present studies, critiques, design-led work, and visions of blockchain applications.
Bettina Nissen, Larissa Pschetz, Dave Murray-Rust, Hadi Mehrpouya ¡ 6 authors
Design and HCI researchers are increasingly working with complex digital infrastructures, such as cryptocurrencies, distributed ledgers and smart contracts. These technologies will have a profound impact on digital systems and their audiences. However, given their emergent nature and technical complexity, involving non-specialists in the design of applications that employ these technologies is challenging. In this paper, we discuss these challenges and present GeoCoin, a location-based platform for embodied learning and speculative ideating with smart contracts. In collaborative workshops with GeoCoin, participants engaged with location-based smart contracts, using the platform to explore digital 'debit' and 'credit' zones in the city. These exercises led to the design of diverse distributed-ledger applications, for time-limited financial unions, participatory budgeting, and humanitarian aid. These results contribute to the HCI community by demonstrating how an experiential prototype can support understanding of the complexities behind new digital infrastructures and facilitate participant engagement in ideation and design processes.