Is the PDF uploaded to a server?

No. Attestto Verify runs 100% in your browser. Your PDF file never leaves your device. All signature verification, certificate chain validation, and integrity checks happen client-side using the Web Crypto API. No backend, no data transmission.

What digital signatures can Attestto Verify check?

Attestto Verify supports PAdES (PDF Advanced Electronic Signatures), CAdES, and standard PKCS#7 signatures. It validates against Costa Rica's Firma Digital PKI (BCCR/SINPE/MICITT) and can bridge to any national PKI via the did:pki resolver at resolver.attestto.com.

How does cross-border PKI verification work?

When you verify a document signed by a foreign PKI, Attestto derives a did:pki identifier from the certificate and resolves it via resolver.attestto.com. If the resolver knows that country's PKI, it returns the CA's public key and the verifier can validate the entire chain — no manual trust store configuration needed.

Is Attestto Verify free?

Yes, completely free and open source under the Apache 2.0 license. Document verification is a citizen right in the Attestto architecture — it will never have a paywall. Source code is available at github.com/Attestto-com/attestto-verify.

Can I verify Costa Rica Firma Digital documents?

Yes. Costa Rica's full BCCR PKI hierarchy is supported — including Persona Física, Persona Jurídica, and SINPE certificates. The verifier validates the certificate chain, checks document integrity, and shows the signer's certificate details. It works with any PDF signed using Firma Digital.

Verify any document.
Nothing leaves your device.

Attestto checks the integrity, digital signatures and certificate chains of any signed PDF, entirely inside your browser. No upload, no server, no account.

Verify a document See how it works

Online verifier

Bytes ever uploaded

Signature standards checked

100%

Runs in your browser

Browsers supported

National PKIs supported

What gets checked

Integrity

Every byte is hashed with SHA-256 and compared against exactly what the signature covers, so any edit made after signing shows up immediately.

Signature validity

PAdES, CAdES and raw PKCS#7 signatures are parsed and checked against the document's own byte ranges, not just detected, but proven valid.

Certificate chain

Certificates are walked back to a trusted root, including Costa Rica's CR Firma Digital PKI, so you know exactly who signed and who vouches for them.

Security scan

Embedded scripts, auto-actions and remote objects are flagged before the file is ever opened in a reader.

Privacy by construction

Your file never leaves your device

Verification runs in the tab that's already open, there's no upload, no server round-trip, and nothing to configure. Close the tab and the file is gone. The code is open source, so you don't have to take our word for it.

View source

Check chain of custody in the browser, in seconds.

Supported standards

Signature types

PAdESCAdESPKCS#7

Recognized PKI

CR Firma Digital

Filled: chain validated against a trust anchor resolved on demand via resolver.attestto.com (did:pki). Outline: certificate recognized (issuer, type, national ID); chain validated when the resolver publishes that PKI.

Capabilities

Zero upload Client-side Open source X.509 ByteRange Forensic audit

Browsers

ChromeFirefoxSafariEdge

Take two seconds to know for sure

Drop in a signed document and see exactly what it proves, no account, no upload, nothing installed.

Verify a document View source

Verify any document.Nothing leaves your device.

Technical Audit