Use Case

Case Study: Cooperation between DATEV eG and Lissi for the issuance of verifiable certificates into ID-Wallets.

Co-Founder and Chief Adoption Officer Adrian Doerk
Adrian Doerk
Adoption Executive
June 17, 2024
This Article explores the Cooperation between DATEV eG and Lissi for the issuance of verifiable certificates into ID-Wallets

Description of the Use Case

In January 2022 DATEV eG began to use verifiable credentials with the internally developed CovidSHIELD app to present Covid-19 PCR test results to employees in the Lissi Wallet.

The PCR tests are carried out in an internal test center, which uses pool tests and thus works very efficiently. In a pool test, up to 35 people (usually from the same work area and shift) are grouped together in a "pool".

Given the pool test is negative, all employees which are part of the pool receive a credential confirming the test status. This status can then be used to access the office venue by presenting the proof to the doorkeeper.

Around 1.400 employees were able to use the convenient testing solution to access their offices. In total more than 470.000 test results have been issued.

DATEVs goal is to prevent their employees from an Covid infection and to have a safe working space. As operator of a critical datacenter and print solutions infrastructure (VAT accounting for a vast majority of German enterprises and over 14 million payrolls per month) DATEV uses covid group testing within their own PCR test centers.

The group testing approach saves time, material costs and makes it possible to operate a PCR-test center with response times of a few hours for more than thousand employees each day. Within peak times up to 25.000 tests per week were done and attested to employees.

This resulted in more than € 2.1 million in savings compared to individual PCR-testing of DATEV employees in the external laboratory market.

Key objective was to enable employees secure, fast and convenient access to the office space with the following requirements:

  • Efficient testing procedures (pool tests)
  • Convenient and fast issuance process of test results with minimal training requirements for the laboratory personnel.
  • Enforcement of limiting access to the office facilities to negatively tested employees
  • User centric credential management of the test results for employees

In addition to the above-mentioned objectives, the following results were achieved:

  • Cost efficiency, since only a front-end had to be developed with no additional costs for software licences.
  • Data sovereignty for the organisation as well as employees
  • The issuance and verification processes are in full control of the organisation. 

Technical integration

The use case is currently used by more than 700 employees and over 5,900 verifiable certificates have already been issued. So far, there have been no problems with performance, availability or memory consumption.

From a technical point of view, the following components are used:

  • Keycloak as access protection (only the pool masters can access the CovidSHIELD app after correct authentication)
  • The self-written CovidSHIELD app to establish the connections to the Lissi wallets and to enter the test results
  • The Aries Cloud Agent Python ("Aca-Py") for communicating with the BCGov test network and issuing the proofs to the Lissi wallets
  • The backend component for the business logic
  • The BCGov test network to store the decentralised identifier (DID) of DATEV, the schema and the credential definition based on it for the certificates
  • The Lissi ID-Wallet


Paumgartnerstr. 6–14
90429 Nürnberg

Lissi GmbH
Eschersheimer Landstr. 6
60322 Frankfurt

This article was originally published on 24th February 2022 on

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