[Rats] Re: EAT profile mechanics: ueid vs sueids for a resettable value, and current practice for profile identifiers

[Laurence Lundblade <[e-mail]>]

You should use sueid. The sueid text says "Examples of life-cycle events are change of ownership, factory reset, ..."

LL

> On Aug 30, 2026, at 4:10 AM, Mohamad Khalil Yossif <mohamad=[e-mail]> wrote:
> 
>> 1. ueid or sueids for a value that changes on factory reset
>> 
>> draft-yossif-psea profiles an EAT token and puts a per-deployment
>> value in ueid. The value is re-derived when the device identifier is
>> regenerated - a factory reset, or on iOS the loss of the Keychain
>> entry.
>> 
>> Section 4.2.1.1 says a UEID is permanent and MUST NOT change for a
>> given entity. Section 4.2.2 describes a value that MAY change on
>> entity life-cycle events, gives factory reset as an example, and lets
>> a profile specify the triggering events and carry a label.
>> 
>> Read plainly, a per-deployment value that changes on a life-cycle
>> event is an SUEID and not a UEID. If that is right, I have the wrong
>> claim rather than the wrong derivation, and I would rather move it
>> once, deliberately, than ship a revision that leaves the claim
>> selection wrong.
>> 
>> The question is narrow: is the permanence requirement in 4.2.1.1
>> meant to bite on a value regenerated by a factory reset, or is that
>> within what a UEID may do? A one-line view from anyone who was in the
>> room for 4.2.1 and 4.2.2 settles it.