Component 1.9 - Security And Data Management (Finished) Flashcards
What can be used to improve network security?
Encryption techniques, user access levels, suitable passwords
What do user access levels do?
User access levels define which change/view selected stored data. It allows certain users read/write access to data on a computer system
Why would user access levels be used on a network?
Certain users don’t need to access all data so user access levels are used to keep them from viewing/changing it. E.g. an administrator in a company should have access to all data but an assistant should not have access to confidential data
What do passwords do?
Passwords are used to prove a person’s identity to a computer system allowing them access to it
What is a brute force attack?
Using programs to try multiple password guesses in quick succession
What is the problem with short, simple passwords?
Another user can easily guess them and a hacker could use a brute force attack
How do you calculate the number of attempts needed to brute force a password?
Attempts = number if characters^password length
What is a suitable password for network security like and why?
A suitable password should be long and use a combination of different characters (upper case, lower case, alphanumeric) as it will be harder to guess and take longer to brute force due to more characters available and a longer length
What is encryption?
Encryption is the conversion of data using an algorithm into cyphertext that can’t be easily understood by people without the decryption key
Which logical operator is often used for encryption?
XOR
How is the xor logical operator used for encryption?
During encryption, the XOR logical operator is used on the data and a key. (If data is 10101010 and key is 11110000, you do 1 XOR 1, 1 XOR 0 and so on to get 01011010). The data is encrypted now.
What is a ‘key’
A ‘key’ is a secure binary number, known only to the sender and recipient
How is data encrypted using XOR decrypted?
The encrypted data can be XOR’d with the key once again to regain the original data
What is compression?
Compression is the process of making a file size smaller
What is the advantage if compression?
Compression allows for more data to be stored on the disk and for files to be transferred faster.
What are the two primary compression methods?
Lossy and lossless
What is lossless compression?
Lossless compression is a data compression technique using an algorithm to compress data into a form that can be decompressed at any time with no loss. (The file is returned to its exact original form)
When is lossless compression used?
Lossless data compression is used when any loss of detail (e.g. word document) could have a
Really bad effect
Give an example of lossless compression?
Replacing ‘the’ in a word document with the character @
What is lossy compression?
Lossy compression is a data compression technique that compresses the file size by discarding some data
How is the compression ratio calculated?
Original file size / compressed file size
What is lossy compression used for?
The compression of multimedia data (sound, video)
What are network policies?
Network policies are documents written to outline the rules users are required to follow while using a computer network. Following publication, users need to adhere to the rules
What are some typical rules set out in network policies?
- List of unacceptable types of websites
- Activities not allowed on the network (e.g. gambling)
- unauthorised software