#covid-19 #tracing #contact


Implementation of the apple/google contact tracing protocol

3 unstable releases

0.2.1 Apr 12, 2020
0.2.0 Apr 12, 2020
0.1.0 Apr 12, 2020

#1294 in Encoding


377 lines


This crate implements the apple/google proximity contact tracing.

The version of this implementation is the initial reference spec from April 2020.


  • chrono: Adds timestamp operations to all structs (on by default)
  • serde: Adds serde support (implies base64)
  • base64: Adds base64 encoding/decoding through Display and FromStr

Broadcast Example

To broadcast one needs a tracing key and the rolling proximity identifier (RPI) for a given time. The RPI is normally created from the daily tracing key but there is a shortcut to derive it automatically:

use contact_tracing::{TracingKey, DailyTracingKey, Rpi};

let tkey = TracingKey::unique();
let rpi = Rpi::for_now(&tkey);

Infection Checking Example

Infection checking uses the daily tracing keys directly:

use contact_tracing::{TracingKey, DailyTracingKey, Rpi};

// normally these would come from the internet somewhere
let tkey = TracingKey::unique();
let dtkey = DailyTracingKey::for_today(&tkey);

for (tin, rpi) in dtkey.iter_rpis().enumerate() {
    // check your database of contacts against the TIN and RPIs generated
    // for each daily tracing key downloaded.  The TIN should be within
    // some reasonable window of the timestamp you captured.

License: Apache-2.0


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