Explainer changes for how currency-related things work

[morlovich]

No description provided.

[trentunderwood]

In this mode (seller currency enabled), all APIs like event reporting, debug event-level loss reporting, and private aggregation will see the converted (bid) values

Question regarding this point: Why can't the seller receive the exact bid in its original currency in reportResult()? It is important that the seller can invoice the buyer the exact amount that was returned from generateBid(). Additionally, it introduces additional risks to the buyer. For instance, what if the seller uses an unfavorable conversion rate? The buyer cannot know about this in advance and won't be able to do anything about it.

Can we change this behavior to allow reportResult() to receive the exact original bid value in its original currency?

[morlovich]

Thanks for the feedback; that's a good point (though beware of rounding rules!); I am working on changing it (well, almost ready to mail to the -code- CL), but one bit of warning: the behavior will be different between M114/115 and 116+.

[michaelkleber]

Hey @trentunderwood Please do note that the values passed into the reporting functions are rounded, so that they only have 8 bits of mantissa. Please see #486. The work going on here is about currency; the rounding of bid values for privacy reasons is separate.

[trentunderwood]

Thank you!

I am working on changing it

Do you mean that you are changing the bid passed to reportResult to be in the same currency that was returned from generateBid? Even if the bid is fuzzed a bit, it would still be very helpful for generateBid and reportResult to use the same currency.

[morlovich]

Thank you!

I am working on changing it

Do you mean that you are changing the bid passed to reportResult to be in the same currency that was returned from generateBid? Even if the bid is fuzzed a bit, it would still be very helpful for generateBid and reportResult to use the same currency.

Yep. See https://chromium-review.googlesource.com/c/chromium/src/+/4573913 as well as changes to this pull request.
Note that this is only about reportResult itself, things like private aggregation keyed off reportResult still get things in the converted currency.

[trentunderwood]

That sounds great - thank you!

[JensenPaul]

I'm still somewhat confused, so I added some clarification rewordings and asked some verifying questions to make sure I'm understanding this properly.