Applies to: All editions
Purpose
A SHA-256 fingerprint identifies the exact byte sequence of a file with a cryptographic hash. PDFSanitize can calculate separate fingerprints for the original PDF and the sanitized output.
These values help prove which files were associated with a particular sanitization and verification record.
Calculate hashes during sanitization
The Calculate SHA-256 hashes option is enabled by default in the predefined profiles. When enabled, PDFSanitize records the source hash and final sanitized-file hash as part of the sanitization result.
Hashes during verification
Verification requires file fingerprints for its record. If the sanitization step did not already store them, PDFSanitize calculates the source and output hashes when verification runs.
Where hashes appear
Fingerprints can appear in:
- The Verification tab;
- Copied verification summaries;
- TXT, PDF, CSV, and JSON reports when available;
- Enterprise Certificates of Sanitization.
Use hashes for evidence matching
When retaining or transferring a sanitized document:
- Preserve the report or certificate containing the expected output SHA-256.
- Store or transmit the sanitized PDF through the approved channel.
- Recalculate the file’s SHA-256 with an approved tool when independent confirmation is required.
- Compare the complete value, not only a short prefix.
A matching hash establishes byte-for-byte identity with the recorded file. It does not by itself establish that the sanitization policy was appropriate or that the visible document content was authorized for disclosure.