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Re: Minor wording changes
> From: jpp@markv.com
> [Overly specific, move this (good) discussion to the document describing
> the digest algorithm....
> When a keyed message digest algorithm is used (such as MD5), the
> secret key is fed into the algorithm first, followed by the invariant
> fields of the IP datagram in sequence.
> ...
>
> I belive it makes some overly strong assumptions about the nature of
> keyed digest functions. (It seems to assume that there is an ordering
> between the key and the message. That may be common, but isn't
> required.
First, it is absolutely imperative that the invariant fields of the IP
datagram are authenticated. So, that needs to be specified up front!
As another message from Eastlake mentions, the goal is interoperability.
We need to _eliminate_ many options, rather than try to accomodate unknown
possible future schemes.
By specifying that the mechanism will always be used in a single
standard way, we make it easier to drop another algorithm into the same
code. Over generalization would make that hard to do, and confuse
implementors.
By specifying only 2 algorithms, both freely available, one MUST and the
second SHOULD, we hope to provide enough for the forseeable future.
Both algorithms use this method. Best to stick with what we know,
rather than endlessly hypothesizing future possibilities. That's what
this group did for 2 years....
Bill.Simpson@um.cc.umich.edu