Re: Comments on x942-05 draft

[Russ Housley <[e-mail]>]

Eric:

I am comfortable mandating the effective and real key lengths are the same
for the calculation of the key-encrypting key.  If some policy wants to use
a reduced effective key length for the content-encryption key, thsi can
still be accomodated.

Russ


At 09:14 AM 2/22/99 -0800, Eric Rescorla wrote:
>> Here's some analysis on the RC2 effective key issue, thanks to Burt Kaliski.
>[...]
>Clearly we do have to defend against the partition attack on effective
>key lengths. 
>
>As John suggests, I propose that we place the RC2 effective key 
>length into the the suppPubInfo. However, this leaves us with
>an unfortunate inconsistency, in that for some algorithms it's
>the length and some it's the effective length. One solution
>to this would be to revert to what Stephen Henson has termed
>the X/8 strategy. I.e. make the effective and real lengths
>the same for RC2. This is slightly more tasteful than having
>a bunch of special case language.
>
>Comments? I'd like to get this settled quickly.
>
>-Ekr
>[Eric Rescorla                                   [e-mail]]
>