Check Sum
(see author note at bottom of page)
The checksums calculated are:

1.  a 2 character LRC (Longitudinal Redundancy Check)
2.  a 4 character Internet checksum
3.  an 8 character CRC32 (Cyclical Redundancy Check used by PKZIP)

The ChkSum-W32 program, along with a readme.txt are available for download here.  Software is provided "as is." without warrantee of any kind.  In no event shall the author be liable for any damages.
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Note:  You don't need to execute a setup program writing obscure data to your registry or updating DLLs in your Windows system folder.  Simply proceed as follows:
       1.  Create a directory on your hard disk.
       2.  Unzip this downloaded archive,, into this directory.
       3.  Run ChkSum-W32.exe
P. Kardos
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FDA News Part 11 Compliance Report Vol. 2 No. 23 page 4 states:

"To determine that the hand-signed document is the same as the electronic record, the agency requires that the exact filename of the e-record, its size in bytes, the date and time of its creation and an authentification value, such as a check sum or unique mathematical value, are included on the handwritten copy provided to the FDA."

ChkSum-W32.exe is a Windows based program that will calculate an authentication value (checksum or unique mathematical value) for a file.
Got comments or questions?  Send me an email:
In case you need to validate ChkSum-W32.exe, a suggested validation protocol, the Word document Validation of Chksum-W32 and source code, are available for download here:
The executed validation protocol is available here (pdf format):
Note by Author:  The FDA requirement to use a checksum to link hand signed paper copies to electronic validation documents has generally been superseded by the practice of scanning hand signed paper documents to pdf files.  The pdf file can then be emailed around and printed as required.
Paul Kardos   19 Aug 2012