QX Chain is a scalable, energy-efficient blockchain solution designed specifically for European smart cities and enterprises, utilising a Nominated Proof-of-Stake (NPoS) consensus mechanism.
Can you briefly present your team?
QXChain is developed by a cross-functional team combining blockchain engineering, AI/ML expertise, and municipal technology experience. Our core team includes Zoran Nasteski (Project Coordinator, Business & Stakeholder Engagement), René Krikke (Product and Project Management) Teodor Bogoeski (Protocol/Rust Developer, Runtime Pallets), Hristijan Jankulovski (Backend & DevOps). We’re supported by VizLore and Prof. Dragan Boscovic, who provides scientific guidance particularly on energy efficiency research. Our team bridges technical depth in Substrate blockchain development with practical understanding of municipal digital transformation needs across European cities.
How did you come up with this project idea and what benefits will it bring to the end users?
The idea emerged from a fundamental challenge in the DLT space: blockchain technology promises transparency and accountability, but traditional implementations are too energy-intensive for public institutions with climate commitments, and too complex for municipal IT teams to operate. We saw an opportunity to build green, sustainable blockchain infrastructure specifically designed for European cities.
QXChain addresses this through green-by-design architecture. Our Proof-of Authority consensus uses just four validator nodes instead of hundreds, reducing energy consumption by orders of magnitude compared to Proof of-Work systems while maintaining Byzantine fault tolerance. We’ve implemented bounded on-chain storage patterns that keep the chain lightweight and efficient over time. Our research demonstrated approximately 20% energy efficiency improvement through our consensus architecture, validated with statistical rigor (p < 0.001 across 3,000+ simulation runs).
For municipalities, this means finally having blockchain infrastructure they can operate sustainably, meeting EU green procurement requirements while gaining the transparency and auditability that DLT promises. For citizens, it means public services built on verifiable, tamper-proof records governed locally rather than by distant corporations. We’re initially validating through AI accountability use cases in tourism, but the infrastructure serves any municipal application requiring trustworthy, auditable coordination, from credential verification to service delivery tracking to transparent governance.
How is TrustChain supporting your growth and what role does it play for the next steps in your development?
TrustChain has been instrumental in three ways. First, the funding enabled us to move from concept to production-ready infrastructure, we now have a fully operational four-validator blockchain network on Azure with a complete Python SDK. Second, the ecosystem connections, particularly through OC1-
OC4 outputs on decentralised identity (KILT Protocol), gave us building blocks we could integrate rather than reinvent. Third, the structured deliverable process (D1→D4) imposed discipline that improved our technical documentation and pilot methodology.
For next steps, TrustChain positions us to demonstrate validated, EU-funded technology to municipal decision-makers who are often risk-averse about emerging technologies. The TrustChain association provides credibility that accelerates adoption conversations.
Why did you apply to the TrustChain call and has your vision changed since then?
We applied to OC5 specifically because its focus on “Green, Scalable, and Sustainable DLTs” aligned perfectly with our conviction that blockchain based accountability shouldn’t mean blockchain-level energy waste. The call’s emphasis on energy efficiency challenged us to prove that trustworthy AI infrastructure could be sustainable.
Our vision has sharpened rather than changed. We entered with a broad concept of “trustworthy AI for cities” and emerged with a specific, validated pattern: the “trust-receipt” architecture that keeps computation off-chain while anchoring accountability on-chain. The pilot work in Skopje, Pristina, and Milano confirmed that “municipality-verified AI” resonates with stakeholders — this positioning emerged from TrustChain UCA activities rather than our initial assumptions.
What is the most valuable takeout from the TrustChain project and why was the topic of the Open Call important to you/your team?
The most valuable takeout is validated evidence that energy-efficient blockchain infrastructure can deliver meaningful accountability. Our Monte Carlo power measurement methodology demonstrated approximately 20% efficiency improvement through our PoA consensus combined with off
chain inference pattern, with statistical confidence (p < 0.001). This transforms our sustainability claims from marketing assertions to quantified evidence.
OC5’s green focus was important because it forced rigorous thinking about efficiency at the protocol level, not as an afterthought. This positions QXChain for EU contexts where green procurement policies and sustainability reporting are increasingly mandatory. The topic also aligned with our belief that blockchain adoption in public institutions requires addressing the environmental concerns that have (rightly) made many skeptical of the technology.
Did you establish collaboration with any of the TrustChain teams or plan for any kind of synergies? If yes, what is the biggest potential in such collaborations?
We’ve engaged with the TrustChain ecosystem primarily through integration with KILT Protocol standards for our DID-based worker identity system. Our pallet-qx-kilt-permissions module follows KILT conventions, enabling potential interoperability with KILT-based identity solutions from OC1 projects.
The biggest potential lies in combining our AI accountability layer with identity and data governance components from other TrustChain projects. For example, a municipal deployment could use OC1 identity infrastructure for citizen authentication, OC2 consent management for data governance, and QXChain for AI accountability, a complete trustworthy AI stack built from TrustChain components. We’re open to collaboration with projects exploring similar municipal or public-sector applications.
What are your expectations regarding the TrustChain software ecosystem and its contribution to the NGI priority areas?
We expect the TrustChain ecosystem to demonstrate that European developed, open-source infrastructure can compete with centralised 2 platforms while embedding values, privacy, accountability, sustainability, that those platforms don’t prioritise. The cumulative effect of OC1-OC5 projects should be a portfolio of interoperable components that together address the full stack of trustworthy digital infrastructure.
For NGI priorities, TrustChain’s contribution is showing that decentralisation doesn’t mean fragmentation. By funding projects that build on each other’s outputs (identity → data governance → economics → interoperability → sustainability), TrustChain creates ecosystem coherence. QXChain contributes by proving that AI governance, an increasingly urgent need, can be addressed within this ecosystem rather than requiring separate infrastructure.
What are the next steps for your team?
Immediate next steps focus on three areas. First, completing pilot validation across few cities, to generate comprehensive evidence for our D4 deliverable and post-TrustChain adoption conversations. Second, engaging with municipal technology integrators who can bring QXChain to their existing municipal clients. Third, exploring follow-on EU funding opportunities (Horizon Europe, Digital Europe) to expand from tourism AI to broader municipal AI applications.
Longer-term, we’re positioning QXChain as infrastructure for the emerging EU AI Act compliance market. Municipalities facing 2026 enforcement deadlines need solutions now — we aim to be the open-source, European sovereign option for trustworthy AI infrastructure.
What is the message you would give to new and potential applicants to TrustChain Open Calls?
Focus on a real problem that real users have, not a technology looking for an application. TrustChain’s UCA methodology will push you to validate with stakeholders, embrace this rather than treating it as a checkbox. The projects that succeed are those where technology serves user needs, not the reverse.
Also: be specific about sustainability. OC5’s green focus isn’t optional, you need quantifiable evidence, not just architectural claims. Build measurement into your design from the start.
Finally, leverage the ecosystem. Don’t rebuild what OC1-OC4 projects have already created. TrustChain’s value is cumulative, your project is stronger when it integrates with others.
