Describe the purpose of the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2021). The mark or mark type is shown in brackets.

1. [2] One mark for each correct marking point (Max 2)
2. • The SSL and TLS protocols provide communications security over the internet / network
3. • ... they provide encryption
4. • They enable two parties to identify and authenticate each other
5. • ... and communicate with confidentiality and integrity.
6. [4] One mark for each correct marking point (Max 4)
7. • An SSL/TLS connection is initiated by an application
8. • ... which becomes the client
9. • The application which receives the connection becomes the server
10. • Every new session begins with a handshake (as defined by the (SSL/TLS) protocols)
11. • The client requests the digital certificate from the server // the server sends the digital certificate to the client
12. • The client verifies the server's digital certificate
13. • ...and obtains the server's public key
14. • The encryption algorithms are agreed
15. • The symmetric
16. • ... session keys are generated / defined