Grasping public key cryptography

- [Instructor] Symmetric encryption provides fast, … efficient encryption. … However it requires both the sender … and receiver have the same shared key … which can be a problem in a complex networked environment. … Asymmetric encryption is also called public key encryption … and it uses two keys that are mathematically related. … A public key that you publish and share … and a private key that you keep private. … Scientists developed asymmetric encryption in the 1970s … as a need for securely exchanging … a secret key became evident. … Let's step through the process of encrypting data … that only Bob should see using asymmetric encryption. … We start with Alice sending a secret message … to Bob with plaintext input. … And now we take Bob's public key … and the encrypting algorithm, it then becomes cipher text. … It's sent to Bob who uses Bob's private key … and the decryption algorithm. … It then becomes plaintext output. … And because only Bob has Bob's private key, … only Bob can see the contents. …