For this uniqueness, public-key cryptography is used. Public-key cryptography, as the name suggests, is a system that one key can be made public while the other key must never be disclosed. That's why we call each encryption key a Public Key
and a Private Key or Secret Key
. Since the private key is information only known to me, an action done through the private key has the ability to prove that it is an action done by me. Conversely in the digital world, anyone that holds the private key will have the authority to perform an action. Therefore, the private key is very sensitive information that must be managed secretly.