PAdES

PAdES (PDF Advanced Electronic Signatures) is a set of restrictions and extensions to PDF and ISO 32000-1 making it suitable for Advanced Electronic Signature. This is published by ETSI as TS 102 778.

While PDF and ISO 32000-1 provide a framework for digitally signing their documents, PAdES specifies precise profiles making it compliant with the European eIDAS regulation (Regulation on electronic identification and trust services for electronic transactions in the internal market). The eIDAS regulation enhances and repeals the Electronic Signatures Directive 1999/93/EC. EIDAS is legally binding in all EU member states since July 2014. An electronic signature that has been created in compliance with eIDAS has the same legal value as a handwritten signature.

An electronic signature, technically implemented based on PAdES has the status of an advanced electronic signature. This means that

One important benefit from PAdES is that electronically signed documents can remain valid for long periods, even if underlying cryptographic algorithms are broken.

PAdES recognizes that digitally-signed documents may be used or archived for many years – even many decades. At any time in the future, in spite of technological and other advances, it must be possible to validate the document to confirm that the signature was valid at the time it was signed – a concept known as Long-Term Validation (LTV).

The PAdES standard, ETSI Technical Specification (TS) 102 778, introduces a number of adaptations and extensions to PDF to satisfy the Directive's requirements. ETSI will feed these European-specific elements back into ISO for inclusion in the next release of the PDF standard, ISO 32000-2.

An electronic signature is a paperless way to sign a document using a unique credential associated with a given person that is logically attached to or associated with the document, carrying an authority equivalent to a handwritten signature. It can be used to authenticate the signer as well as to detect any changes in the document made after it was signed. Electronic signatures are recognized as a catalyst to electronic commerce, notably Internet transactions. Availability of electronic signature techniques has already been a major stimulus to eBusiness and eGovernment. Digital signatures are a secure and legally binding means to implement electronic signatures through three cryptographic algorithms:

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