Digital Work Certificate
Introduction
In cryptography, the expressions certification authority, or certifier, or certifier, or the acronym AC or CA (for the name in English Certification Authority), point to a trusted entity, responsible for issuing and revoking digital certificates, using the electronic signature, for which public key cryptography is used. Legally, this is a particular case of Certification Services Provider. A certification authority issues digital certificates, which already contain the necessary numerical identifications and passwords, making available the verification procedure to validate the provided certificate.
The services of a certification authority are mainly used to guarantee the security[1][2] of digital communications via the TLS (Transport Layer Security) protocol, used in web communications (HTTPS) or email communications (SMTP, POP3, IMAP), as well as to safeguard digital documents (for example, using advanced electronic signatures with the PAdES system for PDF documents, or via the S/MIME protocol for emails).
Concept
The Certification Authority (CA) verifies the identity of the applicant for a certificate before issuing it or, in the case of certificates issued with the condition revoked, eliminates the revocation of the certificates by verifying said identity. Certificates are documents that collect certain data about the owner and their public key and are digitally signed by the CA, using its private key. The CA provides its Certification Services that guarantee third parties who trust its certificates and the relationship between a user's identity and their public key. User trust in the CA is important for the operation of the service and justifies the philosophy of its use, but there is no standard procedure to demonstrate that a CA deserves such trust.
A revoked certificate is a certificate that is not valid even if it is used within its validity period. A revoked certificate has suspended status if its validity can be restored under certain conditions.