encrypting to expired certificates

[Doug Barton]

On 9/15/14 2:26 PM, Werner Koch wrote:
> On Mon, 15 Sep 2014 21:22, dougb at dougbarton.us said:
>
>> Imagine this scenario ... Alice sets an expiration date on her key
>> because she knows that after that expiration date her key is:
>>
>
> 0.  Deleted to achieve some forward secrecy.

Yeah, I'm sure there are other scenarios I was not smart enough to 
consider. :)

> Actually the sematics of an expired (sub)key may come from the 1999 or
> so idea of adding features to mitigate the effect of the UK RIP act (or
> whatever it is called now).

Wow, blast from the past. :)  It's not clear to me how you're tying 
those 2 things together though.

Meanwhile, I left out of my previous post my overwhelming dislike of the 
expiration date feature. :)  Robert has a really good point about GnuPG 
not providing policy, and unfortunately a lot of users see the 
"expiration date knob" and cannot resist the urge to twist it, without 
understanding what it means, or why it should (or should not be) used, 
or in many cases even that they themselves can extend the expiration 
date if they choose to.

Frankly I wish the option had never been added to the spec, but 
(thankfully) I'm not in charge. :)

Doug