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
Malware
Malicious software, designed to cause harm
Ransomware
malware that encrypts users files and demands a ransom to decrypt them
Botnet
a network of computers which contain malware allowing them to be controlled by a hacker
Keylogger
malware that records every keypress and sends it to a hacker for analysis
Cyber defences
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
Encryption
Cipher
a method of encrypting text
Plain text
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
Caeser 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