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eRouška Backend Documentation

eRouška = Acronym of Electronic Face Mask in Czech.

This is a custom part of the backend for an exposure notification application based on the Apple/Google joint initiative.
Please read more about:

• Exposure Notifications API
• Exposure Notification Reference Key Server
• Exposure Notifications Verification Reference Server

As expected, besides shared/common part of the backend (provided in repos linked above) each application implementing the A/G protocol has its own specific part - and here comes this repository.

Content

• Terminology
• Database specification
• Firebase functions
• EFGS integration

Terminology

• A/G protocol = Apple/Google joint initiative; Exposure Notifications API
• eHrid = Device ID, unique for each registration, used for identification of the device in the communication between user and epidemiologist. Format eLLLLLLNNN, L = letter N = number [0-9]
• VC - Verification code for upload of users data. Format NNNNNNNN, N = number [0-9]
• Temporary Exposure Key (TEK) = A key that's randomly generated once every 24 hours. It remains on the device for up to 14 days. In the event that there's a positive diagnosis of COVID-19, these keys are provided to the app.
• Rotating Proximity Identifiers (RPIs) = A random ID derived from the device's Temporary Exposure Key, generated every 10-20 minutes. This is the ID broadcasted publicly.
• Diagnosis key = The Temporary Exposure Key provided by the server that has been confirmed to have a positive diagnosis of COVID-19.
• Verification Server = Server responsible for registering devices and handling related functions and queries. This server is also responsible for issuing tokens and certificates for the purposes of upload of diagnosis keys and for matching diagnostic data to the diagnosis keys.
• Key Server = This server is responsible for validating, accepting, storing and deleting diagnosis keys from the infected users and for generating files of the keys to be downloaded by the eRouška applications.
• HAID - Health Authority ID = ID for publishing to Key server on behalf of specific authority, typically a country.

See also official A/G protocol glossary.