[bhawks]

The model updates are not persistently stored and are not accessed individually. The system can only access aggregated averages of updates.

Here is a paper that describes the cryptography protecting user data https://eprint.iacr.org/2017/281

[orbital-decay]

TIL, thanks! I totally missed this part and just assumed it was just another profiling tool. (it's Google, it has to be, somehow...)