Which Is One of the Least Understood Areas of Cybersecurity, But One of the Most Important?

Well, one of the contenders for an answer to this question is digital certificates and PKI (Public Key Infrastructure). Ask a cybersecurity professional about what they are and how they are used, and you might not get a detailed answer. But, they are fundamentally important to the security and trust of many systems and are used in every single Web connection that we make. Without them, we would not know if we were connected to a fake domain or not.

Basically, digital certificates are used to hold either the public key or the public key pair — in a trusted way. In the following, Alice sends Bob her public key, and which is signed by Trent. If Bob trusts Trent, then he trusts the public key. Bob can then encrypt data for Alice, and where she then decrypts with her private key:

Where we normally use public key encryption is with digital signatures, and where Bob signs a hash of a message with his private key, and then Alice proves his signature with his public key. Again, it is Trent who proves Bob’s public key: