The qualified electronic signature (QES) - or digital signature - is the result of an IT procedure, called validation, which guarantees the authenticity, integrity and non-rejection of electronic documents. The digital signature allows users to exchange documents online with full legal validity. All natural persons can have a digital signature: citizens, directors and employees of companies, as well as public administrations. You can contact qualified trust service providers authorised by AgID that guarantee the identity of those who use a digital signature. The list of qualified trust service providers established in the European Union is available here. It is also possible to use the Portable Document Format (PDF) signature format: the Adobe System website illustrates the specifications of the PDF format necessary for the development of further verification products and digital signature generation. The Agency for Digital Italy provides a guide for Affixing signatures and information on signed documents, which also illustrates the signature in PDF format (PAdES).
The use of previous versions of the Acrobat suite is strongly discouraged.