Trifold Card Design
Selective Disclosure of Verifiable Credentials on Paper
Here we present an Eligibility, Immunization, and Health Passport card utilizing four digitally signed QR code stickers. These stickers are simply QR codes printed onto adhesive labels that can then be attached to a user’s physical card (watch the presentation by IDEO's James Small on the design). Our solution is intended to decouple the health information and personally identifiable information (PII) thereby separating the eligibility of the vaccination from the distribution of it.
The idea is similar to the QR code on the back of a driver's license. It is tamper-roof, the QR sticker cannot be reproduced by anyone else as the state's cryptographic private key is a secret. And the resident simply carries this physical driver's license which can be scanned by law enforcement or other purposes.
An Extension of the US Vaccination Card for Covid-19
To accommodate the several-stage vaccination policies that countries have begun to employ, cards will be distributed containing one digitally signed Coupon QR code (i.e. in a similar way the US sends voting ballots). The Coupon is a pre-vaccination registration and can be used for scheduling and eligibility verification systems.
By allowing Vaccinating teams in the front lines to scan a verifiable QR coupon, the workflow eliminates data entry and input errors in the system. Reading and verifying a coupon happens completely offline. The vaccination team does not need access to the internet to complete their procedures.
After the vaccination, the same app that reads the coupon from the user, signs, and prints two QR stickers: the Badge with complete PHI and the Status that simply shows 1 variable, vaccinated or not. This certifies that the coupon holder has taken a vaccine and can be used to safely enter some venues that might require proof of vaccination. The badge also allows the user to upload adverse side effects with authentic dose information.
The Trifold design allows users to show which information they want to disclose at any given point in time. If they open the left wing of the card, they will show their health information: the coupon and the badge. If they open the right wing of the card, they will show their contact information and a flag that represents their vaccination status. When they open both, they see all the information, through the QR codes and through the manually written records in the center.
Selective disclosure offers privacy and control to users
The card can be printed in regular Letter format and fold it down to create the trifold mechanism.