5.5 - Digital Security
2016 - Unit 1
Usernames & Passwords
Usernames must be matched with a secure password to minimise the chances of unauthorised users accessing a system.
Passwords should contain a mix of uppercase and lowercase letters, punctuation and numbers. Passwords should be of a substantial length (at least 8 characters) and should be regularly changed.
Digital Security Measures
Firewalls (see 2.3) prevent unauthorised access to or from a network. Firewalls filter data packets and block anything that is identified as harmful to the computer system or network.
Firewalls can also be used to block access to specific websites and programs.
Encryption is the conversion of data (plaintext) into an unreadable format (ciphertext) so it cannot be understood if intercepted.
Encrypted data can only be understood by an authorised system with a decryption key.
Anti-virus software (see 2.3) scans a system and removes viruses. If left to infect a system a virus could delete data or permit access to unauthorised users.
Anti-spyware software removes spyware on an infected system so hackers cannot view personal data or monitor users.
Organisations should install and regularly update anti-virus and anti-spyware programs.
Permissions is the creation of different levels of file access so that only authorised people can access and change certain files.
There are different levels of file access:
5.5 - Digital Security:
1a. Describe why usernames and strong passwords are necessary. 
1b. State 3 rules for choosing a strong password. 
2. Describe the purpose of anti-virus and anti-spyware software. 
3. Describe the roles of a firewall. 
4. Explain what encryption is. 
5. What are permissions? What are the 3 levels of access?