The Situation
Business Problem
During vaccination rollout, The state needed a way to prove COVID-related events were real and issued by trusted health sources, because paper cards were easy to lose or fake. The state required a secure, tamper-evident mechanism that preserved privacy while still letting businesses and agencies verify authenticity quickly.
The Challenge
We had to design something that state and health entities could write to, that citizens could present, and that verifiers could trust—all without exposing PHI or creating a data-sharing burden hospitals couldn’t sustain. It also had to be resilient to changing public-health guidance and work alongside existing state digital efforts, not replace them.
The Solution
We built a COVID-era blockchain solution that recorded and validated vaccination/test events from approved sources and exposed a lightweight way for authorized parties to verify authenticity, time, and issuer—without revealing more than was necessary.
- 01Permissioned ledger for COVID eventsOnly approved state health or partner entities could write attestations (e.g., vaccine administered, test completed), giving the chain a known set of trusted issuers.
- 02Minimal, privacy-aware payloadsWe wrote proofs and metadata—not raw medical records—to the chain, so verifiers could trust the event without seeing protected details.
- 03Audit and transparencyEvery write was time-stamped and attributable, giving the state an immutable audit trail if proof fraud or disputes arose.