thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Security Fundamentals & Crypto · Foundational

Digital Certificate

Electronic document signed by a CA that binds a public key to an identity such as a domain, person, or device.

Definition

A digital certificate contains the subject, public key, issuer, validity period, serial number, extensions, and the CA's signature. Relying parties trust the certificate if it chains to a trusted root, is within its validity period, is not revoked, and matches the intended name and usage. Most certificates follow the X.509 v3 standard.

Example

openssl x509 -in cert.pem -noout -text displays a certificate's subject, issuer, SANs, and validity dates.

Exam tip

Certificates contain the public key, never the private key.

Don't confuse it with

Related terms