Lifetime and rotation of daily telemetry session identifiers

Determine when the session identifiers in geod’s daily device-sync and usage-summary records change or rotate.

Background

The paper finds that daily telemetry session identifiers remain unchanged for at least 106 days, allowing records from the same handset to be linked over months. The observed duration does not establish the identifiers’ full lifetime or their rotation policy. Their creation and replacement conditions remain unknown.

References

We do not know when these values change, but the record labels suggest that Apple retains the records for 15 months.

— Decoding What iOS Location Services Send to Apple: An LLM Is an Unreliable Analyst but a Useful Toolmaker  (2610.21597 - Leith, 15 Oct 2026) in Section 3.4.2, “Session Identifiers”