Cybersecurity revision

Cybersecurity revision

1. Cyberattacks

   • Defintion:
     • Attempts to compromise a system or obtain unauthorised digital data (hacking)
   • skills:
     • ransomware: malware that encrypts users files and demands a ransom to decrypt them
     • Botnets: a network of computers which contain malware allowing them to be controlled by a hacker
     • keyloggers: malware that records every key press and sends it to a hacker for analysis
     • Phishing: sending a fake email or message pretending to be from a bank or organisation, which tricks users into trying to log on to a fake website, stealing the login details

2. cyber defences

   • Defintion:
     • Techniques and systems to reduce the impact of cyberattacks
   • skills:
     • Security software – often called antivirus software even though it deals with more than just viruses, scans computers for known malware and removes it. Must be kept up to date with the latest malware definitions.
     • White-hat hacking – hacking that is done with the authorisation of the company being hacked. The hacker produces a report of all the vulnerabilities they found, so that the company can fix them.
     • Grey-hat hacking – hacking done without the authorisation of the company, but with good intentions, often the company will be informed of how the hacker was able to gain access
     • Backups – keeping a copy of important data on a different system, so that it can be restored if the original is damaged

3. Encryption

   • Defintion:
     • Altering data so that it can not be read by anyone other than the intended recipient
   • skills:
     • Encrypt and decrypt messages using a Caesar Cipher and a Substitution Cipher
     • Use brute force and statistical attacks to crack simple ciphers
   • key terms:
     • cipher: a method of encrypting text
     • Plaintext – the unencrypted data
     • Ciphertext – the encrypted data
     • Key – some information needed to encrypt/decrypt the data
     • Crack – to read encrypted data without being given the key beforehand
     • Brute Force – crack a cipher by trying every possible key until successful
     • Statistical Attack – crack a cipher by using statistics and estimates of the most likely values
     • Caesar Cipher – a simple cipher, where each letter is shifted a number of places up the alphabet
     • Substitution Cipher – a simple cipher where each letter is replaced by a different letter