Patent filing backs privacy-preserving identity system

The Hashgraph Group and Truesense have filed a European patent application for a digital identity system called Continuous Identity Trust Infrastructure. The system is intended to verify that a person was physically present at a specific place and time without disclosing personal data.

The filing covers more than 44 European countries under a European Patent Office application submitted in April. The companies have also applied for €74.3 million in European Union funding to support plans to roll out the system in regulated sectors including transport, smart city infrastructure and manufacturing.

The proposed system combines ultra-wideband sensing, decentralised digital identity credentials and zero-knowledge proofs. It is designed to create a record showing that a person was present within a defined zone, while allowing third parties to verify the claim without seeing the person's identity or location details.

According to the companies, ultra-wideband radar detects physical presence and confirms signs associated with a living person, including breathing and heartbeat. That event is then linked to a decentralised identifier held in a digital wallet and recorded on the Hedera network as part of a verifiable credential.

The record includes a presence binding token, a zone identifier, a timestamp and a cryptographic hash. The companies argue that this creates an audit trail for sectors where proof of in-person attendance or access matters, while limiting disclosure of underlying personal information.

Regulatory push

The patent filing comes as businesses and public bodies across Europe prepare for tighter rules on digital identity, auditability and cyber security. The companies said the system aligns with the European Blockchain Services Infrastructure and with standards for decentralised identifiers and verifiable credentials.

They also pointed to the EU's NIS2 cyber security regime, the eIDAS2 framework and the EU Digital Identity Wallet model as policy developments that could increase demand for stronger verification tools. Supporters of such systems argue that organisations will need ways to prove a physical event took place without collecting or exposing more personal data than necessary.

The issue has become more pressing in sectors where access rights, compliance checks and attendance records can affect safety, regulation or financial liability. The companies cited transport hubs, healthcare facilities and industrial sites as possible early use cases.

Use cases

One example is physical access control. A person approaching a door equipped with ultra-wideband hardware and carrying a digital identity wallet could be verified at the point of entry and issued a credential showing their presence, replacing conventional badges or codes.

The same model could be applied to ticketing and gate systems at sports venues and entertainment sites, where operators have struggled with fraud involving transferable digital tickets. In healthcare settings, the system could be used to control access to restricted zones where only authorised staff or visitors should enter.

The planned deployment is broad. According to the companies, the funding application submitted under the Important Projects of Common European Interest - Compute Infrastructure Continuum framework is intended to support implementation across national transport systems, smart economic cities and manufacturing industries in all 27 EU member states.

Patent strategy

The companies described the filing as part of a wider intellectual property and market strategy. In addition to the European filing, the invention is also being prepared for submission to the United States Patent and Trademark Office.

The work brings together The Hashgraph Group, which operates in the Hedera ecosystem, and Truesense, which focuses on ultra-wideband sensing and digital identity systems. Their collaboration has centred on linking physical sensing tools with decentralised trust systems for people, devices and autonomous agents.

Stefan Deiss outlined the significance the partners attach to the filing.

"This patent filing represents an important and critical milestone in our roadmap to redefine identity trust infrastructure. CITI is the first solution that cryptographically links a real-world UWB spatial-presence event to a decentralised digital identity credential. This unique invention with Truesense strongly aligns with the progressive direction of EU regulation and meets the digital sovereignty agenda under the IPCEI-CIC program," said Deiss, Co-Founder & CEO, The Hashgraph Group.

Armando Caltabiano set out the sectors the companies are targeting.

"CITI is designed with a compliance-first mindset, while offering spatial presence and decentralized ID across different ticketing and gate systems, smart city components, industry/manufacturing, healthcare infrastructure, and regulated environments. This joint invention with The Hashgraph Group is a distinctive privacy-preserving identity trust infrastructure that converges physical credentials with digital verification systems," said Caltabiano.