Security And Data Management Flashcards
Give an example of an encryption technique.
XOR, SHA256 and Blowfish
What is original data converted into when a complex encryption technique is applied?
Cyphertext
What is lossless compression?
It compresses data into a form that may be decompressed at a later time without any loss of data, returning the file to its exact original form.
Give a lossless compression example.
The word the, is the most frequently used word in the English language.
@ word @, is @ most frequently used word in @ English language.
The string ‘the’ takes 3 bytes, and this is shortened to 1 byte.
How do you calculate the compression ratio?
Original file size
_______________________
Compressed file size
What is lossy compression?
It discards data to reduce the amount of data that needs to be stored.
Acceptable use
They set out rules, including a list of unacceptable types of website that should not be visited and activities that are not allowed on the network, such as gambling and installation of unauthorised software.
Disaster recovery
A policy that gives procedures in the event of a disaster.
Give examples of disasters that are valid in disaster recovery.
Fire, flood, lightning, terrorist attacks
Hardware failure (like power supply unit failing)
Software failure (like virus damage)
Accidental and malicious damage (like hacking)
What are the 3 parts to a disaster recovery policy?
Before a disaster: Risk analysis, preventative measures and staff training.
During the disaster: Staff response - implementing contingency plans.
After the disaster: Recovery measures, purchasing replacement hardware, reinstalling software, restoring data from backups.
Backups
A backup policy sets out how often and to what medium backups are made.
It’s typical that 3 previous backups are kept, the grandfather, the father and the son. When a new backup is made, the grandfather is overwritten and becomes the new son. This is called the grandfather-father-son method.
Archiving
Data held on computer systems is often archived, storing data no longer frequently used, being held for security, legal or historical reasons. This frees up resources on the main computer system and allows faster access to data that is in use.
Name the 4 different types of malware
Viruses (replicate themselves and spread across computer systems)
Worms (self-replicating, identify vulnerabilities in operating systems and enable remote control of the computer)
Spyware (downloaded software, collects user’s data without knowing)
Trojans (useful programs, but provide a backdoor enabling data to be stolen)
6 ways to protect yourself from malware
Anti-virus software Firewall Up to date operating system Latest versions of web browsers Avoiding phishing emails Malicious software removal tool
Examples of acceptable use contents
Includes a list of unacceptable types of websites which shouldn’t be visited.
Includes a list of activities that are not allowed on the network (gambling, installation of unauthorised software).
