Included is the fastest CRC32 implementation ever written for Visual Basic 6. The entire algorithm is written in x86 assembly language (nasm), thus allowing me complete control and of course speed. Included in the project is a timing class and another CRC32 method posted by me which uses asm assisted bitshifting to achieve better speed.
This CRC32 algorithm runs 25X to 100X FASTER THAN ANYTHING ELSE OUT THERE FOR VB6!!! Feel free to download and test/benchmark and see for yourself!
Note: Due to the size or complexity of this submission, the author has submitted it as a .zip file to shorten your download time. Afterdownloading it, you will need a program like Winzip to decompress it.Virus note:All files are scanned once-a-day by Planet Source Code for viruses, but new viruses come
out every day, so no prevention program can catch 100% of them. For your own safety, please:
Re-scan downloaded files using your personal virus checker before using it.
NEVER, EVER run compiled files (.exe's, .ocx's, .dll's etc.)--only run source code.
Scan the source code with Minnow's Project Scanner
If you don't have a virus scanner, you can get one at many places on the net
including:McAfee.com
Terms of Agreement:
By using this code, you agree to the following terms...
You may use
this code in your own programs (and may compile it into a program and distribute it in compiled format for languages that allow it) freely and with no charge.
You MAY NOT redistribute this code (for example to a web site) without written permission from the original author. Failure to do so is a violation of copyright laws.
You may link to this code from another website, but ONLY if it is not wrapped in a frame.
You will abide by any additional copyright restrictions which the author may have placed in the code or code's description.
By the way guys, look forward to more hashing algorithms, encryption algorithms, and the like from me in the future writtenin x86 assembly taylored for use in vb6! (If this comment was disrespectful, please report it.)
I timed the full asm version that I wrote for this release versus a pure vb version that uses tables and math tricks to do the RightShift by 8. The results I achieved were:
asm version * 10,000 operations = ~15ms pure vb version * 10,000 operations = ~600ms
That is quite a speed increase!! :) (If this comment was disrespectful, please report it.)
Amazing piece of work, 5 globes from me! I'm hoping to see similar projects concerning MD5 hashes, AES and RSA algorithms in the near future. (If this comment was disrespectful, please report it.)
Oups. Having tested a 600Mo file : After having change 4 or 5 bytes in the file, the calculated CRC stay the same. Not normal. (If this comment was disrespectful, please report it.)
Sorry, i thought this CRC was calculating file contents. No, it is calculation on a string only. Sorry for mistake. (If this comment was disrespectful, please report it.)
You can calculate file contents easily. All you have to do is read the file and convert the buffer containing the contents into a string (if its not already) and then call the hashing function. (If this comment was disrespectful, please report it.)
Add Your Feedback
Your feedback will be posted below and an email sent to
the author. Please remember that the author was kind enough to
share this with you, so any criticisms must be stated politely, or they
will be deleted. (For feedback not related to this particular code, please
click here instead.)
Download code
7/24/2012 10:42:44 AM: 
