Sigelith Backup
Dated, optionally encrypted backups of your folders on an external drive — browse any version and restore just what you need.
Microsoft Store · coming soon
Sigelith Desktop
Windows 10 (22H2) or Windows 11, 64-bit. Interface in English and Polish. Version history saves space on NTFS drives; on exFAT or FAT32 every version is a full copy.
What it does
Sigelith Backup backs up the folders you choose — documents, photos, projects — to an external drive or another folder. Every run creates a complete, dated version; unchanged files are linked instead of copied, so the history takes only as much space as what actually changed. Moved or renamed folders aren't copied again, and for very large files only the changed parts are written. A five-step wizard sets everything up and shows the outcome before anything is copied. You can browse any version like a folder, see in which versions a file changed, and restore a single file or everything. Backups can be encrypted, run on a schedule or when the drive is plugged in, and pause to ask you when many files suddenly look encrypted. The drive carries a note and a small script for recovering your files without the program. No account, no ads, no telemetry.
- Complete dated versions; unchanged files take no extra space on NTFS drives.
- Moved or renamed folders aren't copied again; large files save only changed parts.
- Browse any version like a folder and see in which versions a file changed.
- Restore everything, a single folder, or files to their original locations.
- Optional AES-256-GCM encryption, with the key derived from your password (Argon2id).
- Daily backups at a set time, or whenever the backup drive is connected.
- Pauses and asks you first when many files suddenly look encrypted.
Back up your proofs — Sigelith Backup
A Sigelith proof holds only the SHA-256 of your document, so it is only useful together with the exact bytes that were stamped. With “Protect Sigelith evidence” turned on, Sigelith Backup backs up your Sigelith Desktop data folder, including the stamp history, and keeps each stamped document exactly as it was stamped, checked against its hash, together with its .beatproof file, in a separate “Sigelith Evidence” store that retention never cleans up. If a document was edited after stamping, the program recovers the stamped version from older backups where it can — the proof itself is always kept — and the “Sigelith evidence” window checks proofs offline and restores documents.
Each backup version can also get a Sigelith timestamp: only a SHA-256 hash of the version’s file list is sent, and the weekly signature is checked with a key built into the program.
Sigelith inside your backups
Four features that tie your backups to Sigelith. None of them puts your files on a server — Sigelith only ever sees hashes.
A time proof for any file
Any file in a sealed backup version can get its own small proof file and a PDF certificate: this file was in the backup at that moment. The proof reveals nothing about the other files and can be checked in Sigelith Desktop or at sigelith.org/verify/.
A backup that can't be swapped quietly
The content audit reads every file of a version back from the drive and compares it with the hashes sealed in the public Sigelith log — not with the file list stored next to them, which could be forged as well. “Last untouched” points to the newest version that still matches its seal.
Hand over a file with proof of delivery
Pick any version of a file — say, a contract as it was in March — and send it with Sigelith Handover in Sigelith Desktop. The recipient confirms receipt with their own key, and the moment of delivery is recorded in the public log.
A time capsule inside your backup
Seal a folder until a date you choose. Nobody can open it earlier, not even us: the keys come into existence only at that moment, on the drand network and the Sigelith key server. The capsule stays in your backup, not on a server, and sigelith.org/capsule/ opens it after the date.
Screenshots
System requirements
Windows 10 (22H2) or Windows 11, 64-bit. Interface in English and Polish. Version history saves space on NTFS drives; on exFAT or FAT32 every version is a full copy.
Privacy
Nothing is sent over the internet unless you turn on one of two optional features: an off-site copy, encrypted on your computer and sent directly to your own S3-compatible storage, or Sigelith timestamps, which send only a SHA-256 hash of a backup's file list to sigelith.org. “Protect Sigelith evidence” works entirely on your computer.
Microsoft Store · coming soon