[dns-wg] KSK lifetimes

On Fri, 5 Feb 2010, Edward Lewis wrote:

> The outcome of the thread was that, if left up to the cryptographic issues, 
> there would be no need to change keys until a key was detected as being 
> broken.  This is because the effective lifetime of a key is not determined by 
> the key itself but rather by the determination of the attackers.  The moral - 
> you only need to change the key in an emergency.

I don't think that was the outcome at all. As I read it, the outcome was
"cryptographers are even more conservative then DNS operators, because key
strength is a function of math & money, but the IETF suggested lifetimes
were very safe".

> The realization that it isn't the cryptography limiting the usefulness of the 
> key to me is "new thinking."  All along I thought that the limitation on the 
> effectivity of a key was the cryptography - but for "good enough keys" the 
> limitation is how comfortable I am going without changing it and how much 
> does it cost to change it.

To that I agree.

Paul