24 Jun How to Create a Vaccine Passport using the Symbol Public Blockchain

By RadioRadio

Just recently, NEMLOG reported on Kitsutsuki-san（”Kitsutsuki-san” means “Mr Woodpecker” in Japanese), who came up with a great idea to utilise the Symbol blockchain. Still suffering from the after effects of coronavirus, he has found a strong use case for using Symbol to develop a vaccine passport platform. The proposed system would allow users to prove that they had indeed received their COVID vaccine.

Kitsutsuki-san forecasts this to be an increasingly pressing need in society and indeed it has become a hot topic in the global media. For example, restaurants, concerts, sporting events and other places where many people congregate may be required to confirm whether customers have been vaccinated before allowing entry to the venue. Vaccine passports are actively being considered by governments across the world to facilitate the reopening of safe international travel. Proving that you have been vaccinated before boarding a flight may become a mandatory requirement in the future. Therefore reliable and efficient methods for proving your vaccination status are required in order to prepare for these eventualities.

Basic principles of the blockchain-based vaccine passport system

Kitsutsuki-san’s  vaccine passport concept is outlined in this article in Japanese, but can be summarised as follows:

• Users requiring a vaccine passport would create a Symbol account.
• Users would visit their health centre with a QR code reporting their Symbol address.
• The health centre sends an aggregate bonded transaction with metadata to the user’s Symbol blockchain address, confirming that they have received the vaccine. This metadata can contain a string that identifies the date of vaccination and could also contain additional information such as the vaccine administered.
• The user must then review the aggregate bonded transaction. If they agree, they would cosign the transaction on the Symbol blockchain. The aggregate bonded transaction requires a signature within 48 hours or the transaction will expire.
• Anyone checking the Symbol public blockchain will then be able to verify that the confirmation transaction has been sent from the national health service and that you have been vaccinated.

This method proves that the vaccinated person and the health centre have agreed that the vaccine was administered and that the data contained in the transaction is correct. Essentially the recipient and issuer of the transaction have signed a contract together on the Symbol blockchain.

Why blockchain?

A blockchain-based solution to a vaccine passport has several benefits over issuing a paper certificate. For example, it is far more convenient to have this record available immediately on your smartphone rather than having to take a paper document with you when you leave the house. Scanning a QR code at the venue to give the staff permission to access the digital vaccination record may also be faster than manually checking a physical vaccine passport.

Kitsutsuki-san raises an important question about the security of the system. How could we prevent a vaccinated person from transferring the private key for their own vaccine passport to someone else that has not been vaccinated? This could easily be solved by adding identification information such as their name or photo to the metadata. With these measures in place the system would likely be more secure than paper-based documents which can be easily counterfeited or lost.

Future applications

This idea is not limited to proving that you have had a vaccination. It can be used to prove that you have been issued anything from a state or other central authority such as licenses, certificates, identity documents, etc. Kitsutsuki-san’s idea means that none of these documents need to be shared to prove that they belong to you. 

This means you can keep the sensitive and confidential data secure, and be able to share with others on an absolute need-only basis. If anyone asks, you only need to provide them with a QR code which will direct them to the transaction confirming that the document in question has been issued to you. The transaction confirmed by your issuing body would be publicly searchable on the Symbol blockchain. This in itself is enough to provide reliable proof of ownership. 

This also demonstrates the usefulness of metadata and the ease of implementation that only the Symbol blockchain can provide. And not only that, but it also gives a strong sense of the potential of Decentralised ID Certification. We expand on this idea and introduce the “NEMscription Public Experiment” in this post.

NineLives

I’m a Symbol and NEM enthusiast and run this blog to try to grow awareness of the platform in the English-speaking world. If you have any Symbol news you would like me to report on or you have an article that you would like to publish then please let me know!