What Is a Visible Digital Seal (VDS)?

In an era where counterfeiting and document fraud cost the global economy billions of euros every year, Visible Digital Seals (VDS) represent a breakthrough in physical-digital security. But what exactly is a VDS, and why should governments, businesses, and citizens care?

A Bridge Between the Physical and Digital Worlds

A Visible Digital Seal is a machine-readable carrier — typically a DataMatrix or QR code, but also deliverable via NFC, URL, or other media (VDS is carrier-agnostic) — printed or embedded on a physical document or product. Unlike a standard barcode that simply encodes a string of characters, a VDS contains cryptographically signed data. This means that the information inside the seal can be verified offline, without any connection to a central database.

The concept was pioneered by the International Civil Aviation Organization (ICAO) for travel documents. It was subsequently extended to a wide range of use cases through the work of VDSIC and the ISO 22381 family of standards (ISO 22376 and ISO 22385).

How Does It Work?

1. Data encoding — The issuing authority encodes relevant information (identity details, certificate data, product serial numbers, etc.) into the seal.
2. Digital signature — A cryptographic private key signs the encoded data, creating a tamper-evident seal.
3. Printing — The resulting barcode is printed on the physical document, label, or packaging.
4. Verification — Any party with the corresponding public key — embedded in a verification app like Otentik Codes Reader — can scan the seal, verify the signature, and confirm that the data has not been altered.

Because the signature verification requires no live server query, VDS works even in environments with limited or no internet connectivity — provided that trust lists have been downloaded and cached on the device in advance.

Why VDS Matters

Fighting Counterfeiting

From pharmaceutical products to government-issued certificates, VDS makes it virtually impossible to forge a document without detection. Any modification to the encoded data invalidates the digital signature.

Protecting Against Quishing

Unlike standard QR codes that can redirect users to phishing websites ("quishing"), a VDS does not contain a URL. The data is self-contained and cryptographically bound, eliminating redirection-based attacks entirely.

Offline Verification

In regions with poor network coverage or in time-critical border-control scenarios, the ability to verify a document offline is a decisive advantage.

Interoperability

Because VDS is governed by international standards (ICAO Doc 9303, ISO 22376, ISO 22385), seals issued by one country or organisation can be verified by another, creating a truly global trust framework.

Real-World Applications

• Travel documents — Visa stickers, emergency passports, and laissez-passer documents.
• Health certificates — COVID-19 vaccination and test certificates adopted the VDS-NC (Non-Constrained) format during the pandemic.
• Tax stamps and excise labels — Governments use VDS to secure revenue collection.
• Academic diplomas — Universities issue tamper-proof digital credentials.
• Supply-chain traceability — Product authenticity verification from manufacturer to consumer.

The Role of VDSIC

The Visible Digital Seal International Council (VDSIC) promotes the adoption and governance of VDS technology worldwide. Through standardisation efforts, interoperability testing, and the development of verification tools such as the Otentik Codes Reader, VDSIC ensures that VDS remains an open, trustworthy, and accessible technology for all stakeholders.