Including the use of public key, private key, plain text, cipher text, encryption, symmetric key cryptography and asymmetric key cryptography. How the keys can be used to send a private message from the public to an individual/ organisation. How the keys can be used to send a verified message to the public. How data is encrypted and decrypted, using symmetric and asymmetric cryptography. Purpose, benefits and drawbacks of quantum cryptography. Purpose of SSL/TLS. Use of SSL/TLS in client-server communication. Situations where the use of SSL/TLS would be appropriate. How a digital certificate is acquired. How a digital certificate is used to produce digital signatures.