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Message digest calculation in a multiprocessor environment

Alessandro Brawerman
Greenhorn

Joined: Sep 22, 2003
Posts: 22
Hi all,
I'd like to know how to recombine previously calculated digest in one final value. I'll explain better:
I have a binary file and I want to divide this file into 4 equally parts. Each of these parts go to a different processor (my machine has 4) and the message digest (currently using MD5) is calculated for that part in each processor. After that I need to recombine the digests into a final value, so that when my client calculates the digest of the entire binary file it obtains the same digest I have. How to recombine the 4 values I got from the processors? Is it possible? Also, would it make any difference in the method to recombine if instead of MD5 I use SHA-1 or SHA-256?
Thanks a lot for the help.
Alessandro.
 
Don't get me started about those stupid light bulbs.
 
subject: Message digest calculation in a multiprocessor environment