Asymmetric ciphers

Asymmetric cryptography refers to an encoding/decoding algorithm that requires two separate keys, known as a public key and a private key.

Let’s say Bob wants to send Alice an encoded message that only she can read. Alice must first generate both a public key and a private key for herself. She sends the public key to Bob, and keeps the private key to herself.

Bob can then use the public key to encrypt his message to Alice; and Alice uses her private key to decrypt it. Since only Alice has the private key, only she can decrypt the message.

You can think of this as Alice giving Bob a lock, but keeping the key for herself.

Alice gives Bob her public key so Bob can encrypt a message, which she then decrypts with her private key.

In this section, we’ll look at one specific example of an asymmetric scheme, namely the RSA system.