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CrunchyBagel / TracePrivately

A privacy-focused app using Apple's soon-to-be-released contact tracing framework.
MIT License
351 stars 27 forks source link

Exposure date #45

Closed own2pwn closed 4 years ago

own2pwn commented 4 years ago

If we always initialize ENTemporaryExposureKey with the same rollingStartNumber of 0, do we get the actual timestamp of contact?

HendX commented 4 years ago

I don't know exactly how this works. The documentation states:

@property ENIntervalNumber rollingStartNumber;
This property contains the interval number when the key's TKRollingPeriod started.

But it doesn't describe what ENIntervalNumber nor what TKRollingPeriod is.

dstotijn commented 4 years ago

It's explained in the crypto spec on page 6.

See https://github.com/dstotijn/exp-notif-crypto/blob/master/crypto.go#L64-L68 and https://github.com/dstotijn/exp-notif-crypto/blob/master/doc_test.go#L10-L20 for an example implementation in Go.

HendX commented 4 years ago

Thanks, this is all fixed in #49 and is now merged.