The AdES family — PAdES for PDF, XAdES for XML, CAdES for CMS-wrapped data — are the ETSI standards defining how an advanced or qualified electronic signature is constructed, embedded and validated. They are what an eIDAS qualified signature is checked against, and they carry the certificates, timestamps and revocation data needed to validate a signature long after it was applied.
AdES
AdES is the rare standard in this catalog where the artifact is legally operative. A signature either validates against the specification or it does not, and the answer has consequences in court. That is a materially different design constraint from a documentation format, and it shows in how thoroughly the market implements it.
- Three profiles, one model - PAdES embeds in PDF, XAdES in XML, CAdES in CMS — the same assurance model, bound to different carriers.
- Long-term validation - Timestamps and revocation data travel with the signature, so it can be validated years later.
- Qualified signatures - The highest eIDAS tier, backed by a qualified certificate and a qualified signature-creation device.
- Machine-verifiable by design - Validation is a computation, not a judgement — which is why this corner of the market publishes.
This family is the control case in The State of Legal & Compliance APIs. Its market — e-signature and document automation — leads that report on every measure: 32.6 average against a market 24.9, 55.0% publishing a machine-readable contract against the contract-management segment’s 18.2%, and the highest agent-readiness in the cohort. The difference is a legal requirement to be verifiable, which unlike a requirement to disclose cannot be satisfied with prose.
Referenced in API Evangelist papers
This standard shows up in my published research. These reports read the machine-readable evidence provider by provider — and put this standard in the context of a real sector.
The State of Legal & Compliance APIs
The one legally operative, machine-verifiable artifact in the market — and its segment leads on every measure, publishing at 55.0% against contract management's 18.2%.
