In two recent blog articles (here and here) I have called out the USPTO for programming Patentcenter so that its Acknowledgment Receipts list false information about what a filer uploaded in Patentcenter. The practitioner wishing to independently check such things will thus be interested to know how to calculate a SHA-512 hash (Wikipedia article, what the USPTO calls a “message digest”) of a PDF or DOCX file on the practitioner’s hard drive. One way to do this is with a command-line utility within Microsoft Windows.
Here is how to do it.
Suppose you have a file called “x-410.pdf” on your hard drive and it is in your folder called “C:\temp”. Suppose you wish to calculate the SHA-512 hash of this file (what the USPTO calls its “message digest”).
You can open a command line window and navigate to that folder. Having reached that folder, type a command line using the “certutil” (Microsoft documentation) command like this:
C:\temp>certutil -hashfile x-410.pdf sha512
SHA512 hash of x-410.pdf:
CertUtil: -hashfile command completed successfully.
Now you have the hash. If you were to upload this PDF file to EFS-Web or to Patentcenter, you could compare this hash with the hash appearing in the Ack Receipt.
Given that EFS-Web or Patentcenter are likely to fail to actually preserve the uploaded file intact within IFW, you will probably want to make a special point of preserving the uploaded file locally in some very safe place. The preserved file, along with the ack receipt, probably should be preserved for the life of any issued patent, that is for the term of the patent plus the statute of limitations (six years).
Update: See in the comments below that alert readers have provided links to a variety of handy tools for calculating or displaying the SHA-512 hashes (message digests) of files on your Mac, Linux, or Windows computer.