AntiCov: Restart business in Corona-free areas

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This technology is developed by the team around the KILT Protocol to enable COVID-19 harmlessness Credentials that will allow people who passed a quick test or are immune and not contagious anymore to move freely. These Credentials will be self-sovereign data that is created and stored in a decentralised way to prevent data hoarding or theft.
The apps for these Credentials are open source to ensure transparency of the implemented processes and will be distributed without license fees to ensure that everyone who wants, can use them. Ideally a trusted authority such as a government of a country, a state or a community delegates their trust to labs that have proven the ability to conduct such tests and are trustworthy in issuing AntiCov Credentials.
Then, citizens who are already cured or are not currently infected with the COVID-19 virus will have their blood tested or get a quick-test at these labs, will receive an AntiCov Credential and will be more free in moving in the public space, allowed to work with persons more at risk and enjoy the company of friends, family member or business partners, ideally if those also have the Credential. In addition, AntiCov Credentials can be used to revive tourism in COVID-19 free areas and to keep these areas clear of the virus.

The team around KILT has developed the necessary technology and app and will be happy to supply it to governments and users.


Due to COVID-19, there have been quite a few restrictions to prevent infections. In some areas the measures have been so effective, that soon no one there will be infected anymore. These areas will be able to re-open for business and tourism, at the same time not challenging their achievements against the virus.

Therefore, it must be ensured that infected persons are kept out of the COVID-19 free areas. For anyone who wishes to enter such an area, that means that they must prove with a quick test or with an antibody test, that they aren’t infected.

This proof can be implemented as an electronic certificate on a smartphone app. The person using the app is identified by a selfie, which is stored on the app and electronically linked to the certificate. This is achieved by baking a hash value of the picture into the Credential, which ensures that

a) The presenting person’s face,

b) The picture shown on the app, and

c) The hash of that picture in the Credential must match.

The certificate is issued after a test by a trusted entity (e.g. lab) and can be revoked when the person leaves the COVID-19 free area, if they could get infected again. This is achieved through blockchain technology. A hash of the Credential is stored on the chain, where

a) Any verifier can check the validity of a Credential he receives

b) The issuer of the Credential may mark it invalid, so that future validations will fail.

The app holding such electronic certificates can also be used for verifying the validity of certificates, so people can check each other. It can also be distributed to government officials who check the access of COVID-19-free areas such as cities, islands, parts of a country or a whole country.

Why an App based on the KILT Protocol and why AntiCov?

· Self-Sovereignty

A Credential based on the KILT Protocol stays with the user just as a passport does in the real world. In KILT, every attestation process is only triggered, if the person makes a claim about herself and all the data is collected on the Claimer’s device only. The app offers no possibilities to create data pools of personal data and is therefore self-sovereign and follows the principal of data-minimisation.

· Anonymous

The system does not store any unnecessary data, like the name of the Claimer. Data which is not stored cannot be hacked, stolen or tampered with.

· Tamper-proof & revocable

A hash of the Credential is stored on the blockchain, so anyone offered to check the claim, can look it up on the blockchain to see, if the Credential was

a) issued by a trusted authority,

b) issued to the person standing in front of the verifier,

c) and if the Credential is still valid or had been revoked in the meantime.

AntiCov only uses the user-generated public-private-key pair and a photo taken by the user to identify the user and to prove the user is virus-free. No other data is ever stored in any place. This concept of data-minimisation results in better data security. Data which is not collected, not stored and not sent around can neither be stolen, nor tampered with or nor be misused.

How to receive a Credential:

The upper part of the graphic shows how a user will get a Credential. The Claimer (User) shows her app to the Attester (1), the Attester then checks if the person standing in front of him is the same person as the one on the app (2). The Claimer then sends her ID and photo with her claim to the Attester (3). After the Attester has checked, if the person and the app belong together (2), if the Claimer (User) is immune or corona-free (4), and both is true, he then issues her a credential, which he will send to her app (6) and stores a hash of it on the blockchain (7).

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How to use a Credential:

The lower part of the graphic indicates how to use the Credential to get into a COVID-19 free area. The Claimer (User) shows her app to the Verifier (1), who checks if the Credential and the person belong together (2). The User sends the Credential to the Verifier (3) who checks if the Credential is valid and matches the picture (4). If yes (5), the Claimer (User) is admitted and may enter (6).


We would be happy to receive feedback and your ideas, as we are still implementing the app, hoping that the research on the antibody tests goes well and to get such Credentials accepted by authorities as means to get relief from measures.

We will soon provide you with more information about our ideas and our progress. We plan to release the app and the source-code within the next couple of weeks.

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KILT is a blockchain protocol for issuing self-sovereign verifiable, revocable, anonymous credentials and enabling trust market business models in the Web 3.0.

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