PAdES signatures in PHP, from B-B to B-LTA
The four PAdES levels define what a signed PDF preserves and for how long. This guide maps each level to its evidence, the NextPDF edition that produces it, and the applicable responsibility boundary.
NextPDF journal
Security
Trace a PDF digital signature from the baseline signing flow through evidence intended for longer validation horizons. The guide compares four signing levels, maps each one to a NextPDF edition, and separates engine output from certificate, trust-service, and process responsibilities.