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Digital Corona Health Certificate

Frequently Asked Questions


Our solution is more than that. It is meant to digitize the corona health status, whether it is “virus positive/negative”, “antibody positive/negative” or even “vaccinated”. We believe that a trustworthy digital version of this is beneficial to allow for smarter handling of the desease and the infection risks.

We think it is indeed very privacy-friendly. No health-related or personal data is stored centrally, but only on the device of the user. Blockchain is only used for verification of lab-data, that verification can only be used by the owner of the test-result. Strong rules for pseudonymisation are in place.

yes, we are open to other EU countries.

the system is only providing a verifiable way of presenting test-results incl. timestamps. The conclusion out of that can be adjusted if new scientifical evidence is available at any time

yes, we are working with extremely well scaling merkle-tree structures

private Ethereum (but others possible, too). The Blockchain is operated by GovDigital, a cooperative between many federal german IT infrastrucutre providers. Therefore the nodes are rund by known and trusted parties on EU territory.

no, we are just storing crypto-hashes that can be used for verification (details next question)

no, incoming data will be aggregated using a two-layered merkle tree based approach with added nonce (random hashes). Hashes on chain do point to top level merkle tree roots only.

not every part (because of the number of partners), but the essential code that creates and verifies hashes and the blockchain anchoring is open-source

yes, we are working on a deeper technical documentation which will be published asap