certificaattype

Certificaattype, in the context of digital certificates, refers to the category or intended use of a certificate within a public key infrastructure (PKI). The type helps clients determine whether a certificate is suitable for a given operation and informs trust decisions made by software that validates certificates.

Certificaattype is typically indicated by a certificate's extensions and metadata, most notably the extended key usage (EKU) extension and the key usage (KU) extension. EKU specifies purposes such as server authentication, client authentication, code signing, email protection, or timestamping, while KU indicates general capabilities.

Common Certificaattype examples include server certificates used by web servers to enable TLS, client certificates for authenticating users or devices, code signing certificates for software integrity, email protection (S/MIME) certificates, document signing certificates, and timestamping certificates.

Standards and policies governing Certificaattype include the X.509 v3 certificate format and related documents, notably RFC 5280, which define EKU OIDs and usage constraints. Certification authorities issue and manage certificates based on defined policies; a Certificaattype may affect validity periods, revocation practices, and trust anchors (root and intermediate certificates).

In practice, systems enforce Certificaattype to restrict usage, such as disallowing a server certificate from being used for code signing. Properly assigning and validating Certificaattype is essential for secure authentication, data integrity, and privacy in communications and software deployment.