1. Network Security Secure hypertext transfer protocol (https) Cookies Public Key Cryptography

2. Secure Socket Layer (SSL) Uses the https:// protocol Tutorial 1 Tutorial 2

3. Cookies Basic usage Cookies tutorial for web developers

4. Public Key Cryptography Cryptography has been in use for 2,000 years – mainly for military use.military Simple XOR encryption: –101001010101Original –101010101010Encryption key –000011111111Result – meaningless! –101001010101Decrypted -> original.

5. Your message is prepared in plain text and is readable and printable by you and others... Your message is prepared in plain text and is readable and printable by you and others... 1010011010101101100100110101011010 Original message Received message EncryptionDecryption ? Encrypted message Public Key Cryptography Private KeyReceiver’s Public Key

6. Public key cryptography (2)