#23unit 1technology solutions

Digital certificate

Verifiable digital identity issued by a CA.

Verifying Amazon with a digital certificate

Before placing an order on Amazon, your browser requests Amazon's digital certificate. The certificate contains Amazon's public key and is signed by a trusted CA. By verifying the CA's signature, your browser confirms the site really is Amazon — not a spoofer — and the 'https' lock icon appears.

Real-world

VeriSign is a well-known CA. Pretty Good Privacy (PGP), invented by Phil Zimmerman in 1991, is one of the most widely used e-mail public key encryption software tools.