Verify

Check any signed PDF against Solana.

No login. No upload to our database. Drop in a PDF signed with BlockSign and we'll recover the embedded transaction, fetch the on-chain stamp, and confirm the file's SHA-256 content hash matches.

Verify

Upload a signed PDF

We'll read the embedded Solana tx signature, fetch the on-chain stamp, and confirm the file's SHA-256 content hash matches.

Drag & drop a signed PDF, or click to browse

For developers

Don't want to trust this page? Verify it yourself.

The verifier behind this form is open source. Clone the repo, point the CLI at a signed PDF, and it will fetch the on-chain stamp from Solana and re-derive the content hash — identically to what this page does, without ever calling BlockSign.

Only the verifier is open source. The BlockSign platform itself is closed.

Quickstartopen source

Clone

bash

$ git clone https://github.com/blocksign-verify/verify.git

Verify a signed PDF

bash

$ node dist/cli.js ./signed.pdf

github.com/blocksign-verify/verify protocol spec