You should not have to trust an archive. You should be able to check it. A cryptographic hash makes that possible in about two minutes with software already on your computer.
The Steps
- 1Download the source document
Use the “Open public source file” link on any evidence page. Save it without renaming or re-saving through a PDF viewer, which can alter bytes.
- 2Open a terminal or command prompt
On Windows, use Command Prompt or PowerShell. On macOS, use Terminal. On Linux, any shell.
- 3Run the hash command
macOS or Linux: shasum -a 256 filename.pdf — or sha256sum filename.pdf. Windows: certutil -hashfile filename.pdf SHA256
- 4Compare to the published manifest
Open the source manifest and find the line for that file. Compare the full 64-character value, not just the first few characters.
- 5Interpret the result
Identical values mean the file has not changed since it was hashed. Different values mean something differs — most often a re-save by a PDF viewer, so re-download before concluding anything.
What the Record Shows
- Hash verification proves integrity, not provenance. It shows the file has not changed; the source of the underlying document is established separately by its production history.
- The publication standard governing every document on this site is set out in the source-of-truth standard.