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.

Commonly confused · Security Fundamentals & Crypto

Digital Signature vs Digital Certificate: What's the Difference?

A digital signature is a hash of data encrypted with the signer's private key, proving integrity, authenticity, and non-repudiation. A digital certificate is a CA-signed document that binds a public key to an identity so others can trust that key.

Digital Signature

Full definition
vs

Digital Certificate

Full definition
Digital SignatureDigital Certificate
What it isA cryptographic value attached to a message or fileA file (usually X.509) containing a public key and identity info
Created withSigner's private keyIssuing CA's private key signs the certificate
PurposeProve a specific message is authentic and unalteredProve a public key belongs to a specific entity
LifespanTied to one message or documentValid for a defined period, can be revoked
Verified withSigner's public keyCA's public key and the trust chain
RelationshipRelies on a certificate to trust the public keyContains a CA's digital signature
Remember it

The signature signs the message; the certificate vouches for the signer.

Exam tip

Know which key does what: the sender's private key creates the signature and the recipient uses the sender's public key (from the certificate) to verify it.

Tested on

More Security Fundamentals & Crypto look-alikes