Covid-19: Proof of Testing and Immunization … Work, Travel, Visit and more
The Pandemic
The Covid-19 pandemic continues to wreak havoc on the economy. The number of cases seem to be rising steadily while hospitalizations have shown a slight downward trend. Many states within the U.S. and countries around the world have shown some easing of restrictions, partially motivated by the economic distress and people’s frustrations.
According to the Johns Hopkins University dashboard, the total infections worldwide has exceeded 12.5 million. The number of deaths is showing some trends towards flattening or declining. The availability of test kits and testing centers in the U.S. has dramatically increased. Some reasons for the rising cases is due to more folks getting tested for the virus and youngsters taking advantage of the summer. There are other reasons as well which we are not discussing here and is not the intent of this article.
When can I have a normal life back again, go to work, travel overseas, have a drink at the local bar… ?
People are getting frustrated and they want to get out, get back to work, travel, attend school or restart community events. The economy is hurting and many businesses, small or large, are filing for bankruptcy. Small businesses are trying to stay afloat with federal support and cutting non-essential expenses. States throughout the U.S. are trying to ease stay-at-home orders, issuing phase wise guidelines to reopen businesses, and relaxing social distancing measures. The same is true in many countries including India which has seen a spike in cases and no signs of flattening. Travel has substantially reduced, and this is hurting the airline and tourism industry especially during this peak summer season. Many countries are contemplating issuing proof of testing or immunization that can enable folks to travel freely, attend workplaces, visit museums, parks and restaurants.
Research institutions and pharmaceutical companies are racing against time to discover and produce vaccines for the containment and prevention of the virus. Several treatments are also being tested to treat infected patients.
While all these could take time, one area where technology could be effectively applied is for individuals to prove they have been tested or immunized, self-monitor their symptoms, or track their location history to prove that they are not a risk. Any such technology should be easy to deploy and use and limit the exposure of personally identifiable information, yet satisfying individual concerns about privacy.
The Personal Health Wallet
Our innovative team at Chainyard has developed a solution that is in the MVP phase and is still evolving and being tested. We definitely are quite excited about the potential for use.
The solution combines the advantages of a blockchain, mobile app and the evolving standards from the W3C around verifiable credentials and digital identity. The solution is built around the Hyperledger Fabric permissioned blockchain though extending to use other ledgers is easy. The idea of choosing Fabric was for convenience, ease of deployment in a permissioned setting, availability of several enterprise features, easy deployment on IBM Cloud and the ready availability of internally developed and tested libraries.
The DID protocol enables the assignment of pseudo-anonymous digital identities to which verifiable credentials are anchored such as Covid-19 test reports or Covid-19 immunization records.
The mobile application is a simple end user interface to present credentials, enable location history, or capture and manage symptom records at will. The holder’s mobile application serves as a “Personal Health Wallet” while the relying party app supports credential scanning and verification.
— Though the article focuses on Covid-19, the wallet has no restriction on the type credentials that can be stored and presented —
How does the solution work?
The key personas in the solution can be generically identified as the identity holder, issuer and the relying party. The graphic identifies some of the types of actors associated with each persona.
The Identity holder can register oneself providing some key attributes either by going to a clinic or through self-registration via the mobile app onto the application platform. The holder receives a digital identity that can be used to associate credentials collected along their life cycle. If a holder already has a digital identity, then re-registration is not required.
The issuers can be a clinic, hospital, testing center or an attesting trust anchor. For example, when an individual gets to a clinic, a medical professional can register the individual for a testing or an immunization service, capturing key information such as the type of test, date of test, administering entity, the batch ID of the kit being utilized, among other details. Once the testing or immunization service is complete and proofs have computed, a verifiable credential is issued into the wallet of the individual. The individual can now present the credential to relying parties. The issuer based on roles and permissions can revoke the credential providing proofs and explanations. On the other hand, if an individual was issued an electronic or paper copy of a test done anywhere, the person can go to a reliable verifier such as a medical and/or legal professional and get a digital attestation which can be represented as a verifiable credential.
One of the key issues for reopening the economy is assessing the Covid-19 risk posed by an individual. The holder can present credentials to employers, a restaurant owner, at the entry in Disney World or security at the airport. The credential is verified and allows the relying party to take appropriate action.
The graphic in fig.2 shows a typical flow within the solution. The flow represents an example of an attestation.
A clinic has provided an electronic copy of a test report to an individual maybe in their home country. Let us assume that the individual must present the credibility of that report as he/she travels across country boundaries. The holder takes the report to a trusted verifier who is registered on the platform or the clinic where the report was provided and gets its attested. Cryptographic and visual proofs can be associated with the attestation.
Key Features of the Solution
The solution consists of a back-end operational interface and the end-user mobile application. The back-end leverages a permissioned blockchain. The back-end application provides a desktop UI that enables
- Assisted Registration of an individual and obtaining a digital identity or verify an existing one
- Register for a testing or an immunization and record the results and proofs
- Issue verifiable credentials against a completed testing or an immunization service
- Revoke an issued credentials providing reasons and proofs
- Attestation of a paper or electronically issued document
The mobile app for an individual (holder) behaves like a wallet. The app is designed using Google’s Flutter and can work on both Android and IOS. Upon startup, the app displays the list of valid credentials issued to the holder. If the app has connectivity to the internet, it will check, connect, and sync up with its cloud twin.
Depending on who the relying party is, the individual can present the appropriate credential. The credential is presented as a QR code and allows the Verifier app to scan the code and parse out all the details. Thus, the app is designed to work in tethered and un-tethered mode. Therefore it can be used in areas with poor connectivity or in situations where setting up connectivity is not possible in reasonable time.
Now, we have noticed that some business entities request their subjects to maintain a self-recording of their daily symptoms and present as requested. The mobile app enables the individual to record their daily symptoms, temperature and location. This information is recorded off-chain with digital hashes on the ledger. The data can be shared with a relying party at will by the holder.
The adjoining image, shows the screen to record the symptoms, the self-measured temperature and the location where the record was made. When combined with the location history, such data can also be used to calculate patient risk and gain additional insights.
The app has a feature whereby the device owner can voluntarily turn on location capture based on configurable parameters such as frequency or distance. The holder can present their history displayed on a map if there is a request for a certain period, for example the last 14 days.
The complementary verifier app enables the relying party to perform the following several functions such as:
- Scan the QR code (credential or digital identity)
- View details of the credential and verify the associated proofs
- If the credential is associated with an attestation, enable viewing of original document presented for attestation
- Scan the digital identity code and view the digital identity doc (DDoc)
While the solution has other features, it is best to leave the readers with some curiosity to comment and some imagination of what we do for the community. There are other solutions with similar objectives, some using technology whose adoption may be expensive or still far away. I believe in simplicity and ease of use, and most importantly, I work for a solutions company that has made blockchain easy to adopt and embrace.
Conclusion
If you are an employer, medical institution or a public official interested in understanding more about the app and obtaining a demo, please feel free to reach out. We are interested in partners to commercialize the solution and enable restart the economy.
Chainyard is a boutique blockchain services and solutions company. More information can be found here. Also, review the production solution “Trust Your Supplier” which is one of the largest permissioned supply chain solutions based on Hyperledger Fabric. Chainyard helps companies in building enterprise blockchain solutions, establishing consortium and governance, strategy consulting, and security and infrastructure engineering.
The content of this article are the author’s opinion and experiences, and does not necessarily reflect those of Chainyard or its leadership.