Re: [DNSOP] Key sizes was Re: I-D Action:draft-ietf-dnsop-rfc4641bis-01.txt

[Shane Kerr <[e-mail]>]

Paul,

Paul Wouters wrote:
> On Wed, 22 Apr 2009, Shane Kerr wrote:
> 
>> I don't think this is a waste, really. I think if we recommend 1024 as
>> the text does, then we'll have to revisit it in 3 or 4 years.
> 
> Is this for ZSK or KSK? Because if you pick equal sizes, then both would be
> equally vulnerable to the same brute force attack, and often cycling a
> ZSK of
> equal size to the KSK key does not make much sense - the attackers would
> just ignore the ZSK and go for the KSK instead. So using a 2048 ZSK sort
> of implies using a larger KSK. Unless you keep the ZSK for 6 months or so.

Good point. I was only ever considering KSK key length.

I kind of assume everyone will use automated ZSK rolling, and that ZSK
will get rolled fairly frequently, so shorter keys make sense.

--
Shane