Preserve
Originals are opened read-only and never re-encoded, cleaned or overwritten.
Digital evidence workstation for Windows · Local-first
Preserve, compare and document digital evidence, with every step on record.
PROOFDESK keeps originals untouched, records SHA-256 hashes at import, compares files byte by byte and builds reports that keep observed facts, automated signals and examiner interpretation apart.
Free during beta · Windows 10/11 x64 · Works offline
- FactMatches
The SHA-256 recorded at import matches the file as it is now.
- Automated signalMismatch
Extension says .jpg, but the content signature indicates PNG.
- Examiner interpretationExaminer note
Why the file was renamed is a question for the examiner, not the tool.
- ExternalExternal result
Imported ORIGMA report, shown as-is and never re-scored.
Illustrative layout. Example statements, not real case data.
Files travel. Context gets lost.
Screenshots are re-saved, attachments renamed, metadata stripped by messaging apps. Months later, nobody can say which copy is the original, what changed or who handled it.
Which copy is the original?
Exact and near-duplicate copies pile up across folders, devices and chats.
What actually changed?
A different hash shows that bytes differ. It does not show what changed or why.
Who handled it, and when?
Without an append-only log, chain of custody depends on memory and email threads.
Compare
Byte, metadata, text and pixel differences, each listed as its own type.
Record
Every action lands in a hash-chained, append-only audit log.
How it works
Four steps from a folder of files to a package someone else can re-verify.
Import and preserve
Add files or folders to a case. Originals are opened read-only while PROOFDESK streams a SHA-256 hash and records who imported what, and when.
Inspect
Check file signatures against extensions, read EXIF, PDF, ZIP and Office metadata, and place per-source timestamps on a timeline.
Compare
Find exact duplicates and perceptual near-duplicate candidates. Compare Studio shows byte, metadata, text and pixel differences side by side.
Report and package
Export HTML and JSON reports plus a Case Package ZIP whose manifest can be re-verified on another PC.
Built for careful, repeatable work
Each result links back to the original file, its hash and the method that produced it.
Originals stay untouched
Read-only access with a streaming SHA-256 at import. Analysis runs on streams or working copies.
Signature vs. extension
Flags files whose content signature does not match the extension, reported as an observed mismatch.
Metadata inspectors
EXIF, PDF, ZIP and Office properties, read-only. Missing metadata is shown as missing, not as proof of tampering.
Duplicate candidates
Exact duplicates by hash, plus perceptual near-duplicate image candidates for you to review.
Compare Studio
Byte, metadata, text and image pixel diffs, with every difference type listed separately.
Timeline
File system, embedded metadata and import timestamps, each labeled with its source.
Hash-chained audit log
An append-only chain of custody. Each entry carries the previous entry's hash, so later edits are detectable.
Case Package export
A ZIP with a manifest of SHA-256 hashes that can be re-verified on another computer.
Layered reports
HTML and JSON reports that separate facts, automated signals and examiner interpretation.
Works alongside ORIGMA
ORIGMA assesses AI-origin, provenance and integrity signals in individual files. PROOFDESK does not rebuild that detector. Instead, you can import an ORIGMA report you exported yourself, and PROOFDESK attaches it to the case as an external result.
- The imported report's hash, import time and source are recorded.
- Fields are preserved as-is. Unknown fields are kept, not dropped.
- ORIGMA scores are never converted, averaged or re-scored as PROOFDESK results.
- Nothing is uploaded to ORIGMA automatically.
PROOFDESK
What changed in this set of files, and can the process be reproduced?
ORIGMAExternal result
Is this file AI-generated? What do provenance and integrity signals show?
What PROOFDESK does not claim
Clear limits are part of a trustworthy tool. PROOFDESK reports what it observed and leaves conclusions to people.
- It does not detect every forgery or manipulation.
- It never labels a file "100% real" or "100% fake".
- It does not guarantee that anything will be admitted as evidence in court.
- It does not decide what happened. A changed hash shows that bytes differ, not why.
- It does not treat missing metadata as proof of tampering.
- It supports examiners and does not replace expert review.
Frequently asked questions
Is PROOFDESK an AI or deepfake detector?
No. PROOFDESK focuses on preservation, comparison, chain of custody and reporting. For AI-origin signals you can import an ORIGMA report, which is shown as an external result.
Are my files uploaded anywhere?
No. Analysis runs locally on your PC and works offline. Optional OpenAI-based explanations run only when you explicitly request them, after PROOFDESK shows you what would be sent.
Does PROOFDESK modify my original files?
No. Originals are opened read-only and are never re-encoded or overwritten. Work happens on streams or working copies, and each action is written to the audit log.
Can someone else verify my export?
Yes. A Case Package ZIP includes a manifest with SHA-256 hashes. On another PC, PROOFDESK re-checks every file against the manifest and reports each one as a match or a mismatch.
Will my reports be accepted in court?
PROOFDESK cannot guarantee admissibility. That depends on jurisdiction, procedure and expert testimony. It helps you keep a consistent, traceable record of how evidence was handled.
How much does it cost?
PROOFDESK is free during the beta. Free and Pro editions are planned, and pricing will be announced after the beta. Core preservation features will not be locked behind a paywall.
Which systems are supported?
Windows 10 and 11 (x64) first. macOS and Linux are not part of the initial release.
Start a case on your own machine
Your files stay on your PC. Download the Windows beta and keep a record you can re-verify later.
Download for Windows
Free during beta · Windows 10/11 x64 · Works offline