The Hashgraph Group and Truesense have filed a European patent application for CITI, a system that cryptographically binds physical presence to decentralised digital identity credentials.
Switzerland-based The Hashgraph Group (THG) and Italy-based Truesense have filed a joint patent application with the European Patent Office for their Continuous Identity Trust Infrastructure (CITI), a system that combines ultra-wideband spatial sensing, decentralised digital identity, and zero-knowledge proof cryptography to generate privacy-preserving, auditable, verifiable credentials. The application was filed on 4 April 2026 under European Patent Application Nr. EP26425032, designating more than 44 countries across Europe. A parallel application to the US Patent and Trademark Office is also in progress.
How CITI works
CITI operates across three technical layers. Ultra-wideband (UWB) technology first detects that a user is physically present within a defined zone, confirming human presence through radar-mode vital-sign sensing via an on-device machine learning algorithm. The UWB presence event is then cryptographically bound to the user's decentralised identifier, stored in a digital identity wallet, generating a presence binding token and zone presence indicator. A verifiable credential is issued, embedding these elements alongside a timestamp and cryptographic hash anchored on a distributed ledger technology network, creating a tamper-proof, auditable record. A zero-knowledge proof module then enables selective disclosure, allowing third-party verifiers to confirm the credential's validity without accessing personal or location data.
The result is a presence attestation that is cryptographically secure, auditable, and privacy-preserving, linking a real-world physical event to a digital identity credential without exposing underlying personal data.
Regulatory alignment and use cases
The CITI invention is aligned with several EU regulatory frameworks, including eIDAS 2.0 and the EU Digital Identity Wallet framework, which requires EU member states to provide digital identity wallets by the end of 2026, and the NIS2 Directive, which establishes cybersecurity and auditability obligations across the EU. It is also aligned with the EU's Digital Product Passport framework under the Ecodesign for Sustainable Products Regulation, with the first product obligations for batteries taking effect in 2027.
Potential applications span financial services, healthcare, sports and entertainment, and regulated industrial environments, including physical access control, venue entry validation, and hospital zone credentialing. THG and Truesense have submitted a joint funding application under the EU's Important Projects of Common European Interest -Compute Infrastructure Continuum programme to accelerate CITI deployment across national transportation systems, smart cities, and manufacturing industries.
