Cryptography

What is it all about?

Cryptography is also known as encryption. Today we are going to look at public key encryption. You might be thinking: Why is this important?

Public key encryption is used every day, when you see the https in your browser. Public key encryption is at work making sure the data between you and the website is secured and encrypted.

Can't somebody just decrypt it?

Yes but it would take a long time.

Let's imagine John is trying to send a secret message to Tom.

John

Tom

Let's meet at the corner shop at 5pm 

Secret Spy

The message can be read by the secret spy monitoring internet traffic by John.

With Cryptography

John

Tom

Message

Secret Spy

Tom's Public Key

Tom's Private Key

Message

$vo%F43£"Fgegerq$gh4

Real Example

Hello. This is a test!

becomes...

-----BEGIN PGP MESSAGE-----
wcBMA3ZO8E2yqY6jAQf/crd5ThzhxsT0ADUmPZD/Y3WHF7s+h8Edw+JF7g7f3/W6
Oflonv/88pOkbfzwXkCHdGygsyYcfJpNEMxxmd3N9UL/pBDfrY8x67LSlCt6YIqO
HIFK+EdodihmUJEg4tl9BXqE7vHkZrH8slqe1JY6i5nTadCIZful7b8RKuuHJWgP
HibOftLvn/AM7w1EWYJ3RL+s8GV3vKwD2Z5QK0qBfwGFSa/1hKqSI27evKUhyuNs
OHoz78ZyHYQ2UEfZsqlYvCsEcBYzUz7zvmcjiOw+X1wxIZHLabuuNpSTdA42+Ijm
g6qX8xH49sEY5KAu1ScQB9ORM1jgEcvTLEIKOvZGSNJRATEHJYn46sgSUNjFqBjV
0HlBm8DU3ICo22PjY3KLLGM2H25MQcltqQLOYzhnb6mGBBZ6AszNIAf3yJQlTdbh
O68HcmviI2LyWQjP9bUlFGgm
=5Chs
-----END PGP MESSAGE-----