Check out the following VI that ships with LabVIEW 8.0 and later:
[LabVIEW]\vi.lib\utility\MD5Checksum.llb\MD5Checksum file.vi
This LLB is available for download on the Developer Zone, but I decided to include it in the shipping VIs in LabVIEW 8.0. It's a great, 100% G-based implementation of the MD5 algorithm for generating checksums. I've used this VI for a couple of purposes. One was to do checksum matching on the files generated by an installer versus the depot files used to create the installer. Another time I used this VI was in a project where I had a pretty complicated parser that was analyzing text files from disk. When I stored the parsed information from the file, I also stored the file checksum. The next time I needed to load the files, I compared the stored checksum against the checksum of the current revision of the file on disk. If they were the same, I used the stored parsed information instead of having to go through the time-consuming process of parsing the file again.
-D
P.S. - To give credit where credit is due, one of my colleagues on the LabVIEW team, Steven Harrison, was the original author of this VI.
P.P.S. - Check out past nuggets
here.