sertifika

Sertifika is a term with dual usage. In everyday Turkish, sertifika means a certificate—a document that confirms a qualification, achievement, or authorization. In information technology, sertifika commonly refers to a digital certificate, a cryptographic credential used to prove identity and enable secure communications.

Educational institutions issue academic certificates and diplomas; government agencies issue birth, marriage, or professional licenses. Certificates may include the holder's name, the issuer, the date, and the credential details. They are often required for employment, study, or immigration.

In public key infrastructure (PKI), a digital certificate links a public key to an entity's identity. It is issued by a certificate authority after validation and includes the subject name, public key, issuer, validity period, and the CA's digital signature. They are widely used in TLS/HTTPS to secure web traffic, in code signing, and for email signing. The common certificate format is X.509.

Common types include TLS server certificates, client certificates, and code signing certificates; certificates may be domain validated (DV), organization validated (OV), or extended validation (EV). Other variants include wildcard certificates and certificates with multiple domain names (SAN). Revocation mechanisms include certificate revocation lists (CRLs) and OCSP.

Lifecycle and security: certificate management covers creation (CSR), validation, issuance, renewal, and revocation. Security best practices emphasize protecting private keys, using hardware security modules (HSMs), and keeping certificates short-lived or automated. Public certificate authorities such as Let’s Encrypt, DigiCert, GlobalSign, and Sectigo play major roles, particularly in digital authentication and encrypted communication. See also PKI, X.509, TLS, and related standards.