TFM needed ro R

[David Rudder <[e-mail]>]

Hello,
	I'm trying to write a MD2 program.  Applied Cryptography by Bruce 
Schneier says "Append a 16-byte checksum to the message".

Um, dumb question - How do I make a checksum?  Is this the CRC?  Is CRC 
the only checksum?  In any case, does anyone know of an RFC or something 
like that that says how to go about making a checksum?  Applied 
Cryptography doesn't have anything on it (at least, not according to the 
index and I can't remember reading anything).  I've searched the Web and 
found examples in Pascal, C and Forth, but I'd like to understand the big 
picture before writing a new one (I need to do it in Java).  The RFC 
index has two entries with "checksum" in the title, but these seem to be 
IP specific.

On a more conversational note:

RIPEM and SSLeay seem to like MD5.  RIPEM uses MD2 for it's X.509 
certificates but MD5 for it's MIC-Info.  There are a bunch of MD5 
programs out there and a number written in Java.  Bruce Schneier says "I am 
wary of MD5" on pge 441 of Applied Cryptography.  He states before that 
that MD5 hasn't been provven insecure, but weaknesses have been found in 
the compression function.  If he is wary of this algorithm, then why is 
it so popular?  It's by far more prevelant than any other message digest 
I've seen.

			-Dave
		   [e-mail]

I got a coffee mug from Cray Research when they moved out.  Now I can 
drink my coffee while doing 63 other, unrelated tasks.