Scale Soft

Ed25519 Signature Verifier

Verify a photo or PDF

Drop a file signed by ProofKit. We'll tell you if the signature holds, when it was captured, and from what device.

Verification checks the Ed25519 signature against the Scale Soft root certificate. A valid result means the file was produced by a registered ProofKit device and has not been modified since capture. Any alteration — including a single pixel — will cause verification to fail.

How verification works →