#timestamping

A Python service that signs PDFs to PAdES B-LTA with a visible stamp — embedding the timestamp, certificates, and revocation proof, then an archive timestamp — so signatures stay verifiable long after their certificates expire, and verifies signed PDFs.

A Rust timestamp authority that stamps a document's hash with a signed, NTP-backed time per RFC 3161, so PDF signatures stay verifiable after their certificates expire — issuing and renewing its own signing certificate, with public OCSP and CRL.

The digital signature platform of the City Government of South Tangerang: signers prove who they are, sign PDFs to PAdES B-LTA with certificates from the platform's own authorities, and anyone can verify the result — version 2, which I designed, built and operate.