Subject: Re: CALSCH working group minutes

From: "John Stracke" <[email-masked]>
Date: Mon, 22 Apr 2002 14:12:32 -0400

>MD5 is "heavy duty" as the minimum base for CAP authentication.

Heavy duty in what sense? It's widely implemented; it's fairly easy to 
implement from the spec (I've done it); and I don't *think* it takes that 
much CPU.  I just tried it on a 1MB file on my 233MHz Pentium MMX laptop 
running Linux; it took 0.150 seconds of user time (i.e., CPU time spent 
outside the kernel--which is the appropriate number, since the algorithm 
is outside the kernel).  For digest authentication, you typically have to 
do the MD5 on something under 100 bytes.  So, if you've got a gigahertz 
machine serving 100 CAP requests per second (unlikely), you can expect 
about 1/2500 of that second to be in MD5.  If you've got a 25MHz PDA 
submitting an authentication request, MD5 will probably take something 
like 0.150 milliseconds (not seconds).

Of course, this is very much back-of-the-envelope; it'll depend on the CPU 
architecture, for one thing.  But, even if I'm off by an order of 
magnitude, I don't think this is expensive.  And I, for one, don't know of 
a cheaper authentication scheme (plaintext is not an option).

/========================================================\
|John Stracke                    |Principal Engineer     |
[email-masked]   |Incentive Systems, Inc.|
|http://www.incentivesystems.com |My opinions are my own.|
|========================================================|
|"Who died and made you king?" "My father."              |
\========================================================/

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From: [email-masked]
Date: Wed, 24 Apr 2002 12:09:00 -0400

I see there has been a bit of discussion about the XML on iCalendar draft
expiration date.  I will post a correction to the minutes.  Thanks for
catching this and hopefully this has not caused too much of a problem.  If
anyone sees any other items please let me know.