Re: [dmarc-ietf] WGLC ARC-16 concern on Section 5.1.2 - cv=fail should sign greedily

[Dave Crocker <[e-mail]>]

On 8/14/2018 10:28 PM, Kurt Andersen (b) wrote:
> The only reason to affix a seal with "cv=fail" on the end of an ARC 
> chain is to spare all subsequent handlers from having to venture past 
> step 2 in the validation process. Without that, every intermediary and 
> the final receiver (at least those which validate ARC) will have to 
> repeat the entire sequence of validation up to whatever point in the 
> process a failure is determined. 


So the extra mechanism is intended an efficiency hack.

1. The processing being saved is merely normal processing that they'd be 
expected to do for a valid message.

2. I hope we are assuming that failure is not a typical condition

3. In order to save some occasional processing in some cases, we are 
adding mechanism to all implementations everywhere.

This doesn't sound like compelling benefit, which is why I suggest 
removing it.  Absent compelling benefit, simpler specifications is to be 
preferred, IMO.


d/
-- 
Dave Crocker
Brandenburg InternetWorking
bbiw.net