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Unit 9 – Security and data management - Coggle Diagram
Unit 9 – Security and data management
Network security
Unauthorised access to a network can allow the hacker to see all of the stored data.
Risks to data become greater as it is shared across a network.
secure a network requires appropriate level of access and secure passwords and encryption
Network Security: User access levels
It is not sensible or safe for every network user to have access to all the data on a computer system
users access levels define which users can change and view but view but not change not view stored data
It will also specify what software they can or cant access
Network Security: Suitable passwords
passwords add an additional layer of security when accessing a computer system.
strong passwords require the user to have use a combination of upper and lower case letters, numbers and symbols such as @ ! /
sstrong passwords are much harder to guess and will take longer to brute force
Encryption techniques
cryption is using a algorithm that convert data into a form called hypertext that cannot be easily understood by people without a decryption key.
XOR
The XOR logical operator has two inputs and one output. The output is 1 if either A or B are 1, but not both of them at the same time
When encrypting data, the XOR logical operation is performed on the original data and a key..
The key is a secure binary number known only to the sender and recipient. When the XOR is complete, it creates hypertext, which is what is sent to the recipient, for them to decry pt using XOR
the original data r 10101010, is now encrypted and can be transmitted as 01011010.
Compression and compression types
Compression is the process of making file smaller so it takes less disk/memory space.
This allows more data to be stored on the disk
Files may also be transferred more quickly
There are two primary methods that are used to compress files stored on a computer system; these are lossy and lossless.
Lossless
Lossless compression uses an algorithm to compresses data into a form that may be decompressed without any loss of data, returning the file to its exact original form.
It is preferred to lossy compression when the loss of any detail, for example in a computer program or a word-processed document, could have a detrimental effect.
A simple lossless compression on a word processed document replaces common strings such as the with a token such as the symbol @ making a 2 byte saving every time the word the occurs.
Lossy compression
Lossy compression reduces the file size by discarding data.
The technique aims to reduce the amount of data that needs to be stored
Lossy compression is used to compress multimedia data, such as sound and video, especially in applications that stream media over the Internet.
Network policies
network policies are documents outlining the rules that users are required to follow while using a computer network.
Following its publication, network users will be expected to adhere to the rules.
Disaster recorvery
A disaster recovery policy outlines all the processes that must be carried out in the event of a disaster
disasters
fire,flood,lighting, terrorist
hardware failure e.g power supply unit failing
software failure e.g virus damage
accidental and malicious damage, e.g. hacking
Backup
A backup is a copy of data that can be used if the original data is lost.
backup of all data should be made regularly, as the older the backedups data becomes, the less likely it is to match any current data stored on a computer system.
A backup policy sets out whawhere, when and how often backups are made
Archiving
archiving is the process of storing data that is no longer in current or frequent use It is held for security, legal or historical reasons
The process of archiving data frees up resources on the main computer system and allows faster access to data that is in use.