Computer Science - Paper 1
1.2 Memory and Storage
1.2.1 memory
1.2.2 Secondary Storage
1.2.3 Units of Storage
1.2.4 Data storage
1.2.5 Compression
1.4 Network Security
1.4.1 Network Threats
1.4.2 Identifying and preventing vulnerabilities
What is malware?
1.3 Computer Networks, connections and protocols
1.3.1 Networks and topologies
LAN vs WAN
WAN
devices are connected through the internet
used in company buildings in different countries (for Example)
Wide area network
made up of multiple LANs
Covers a wide geographical area
LAN
devices are connected via ethernet cable or WiFi
usually used for single buildings such as schools and offices
Owners are responsible for costs
local area network
Covers a small geographical area
Types of Network
What is a computer network?
A computer network is where computers are linked together, with a cable (ethernet cable) or through the internet. The linked/connected computers are able to share data and resources.
Why might we use computer networks?
We use computer networks for many different reasons: You can share documents easily, you can share devices such as printers, software and storage can be shared across the network, it can be more reliable, backups can be centralized.
What are the disadvantages of computer networks?
They require skills in order to make them, They are expensive to make, they are time consuming to maintain and create
LAN and WAN
What is LAN?
A LAN (Local Area Network) covers a small area such as one site or building, e.g a school or a building.
What is WAN?
A WAN (Wide Area Network) covers a large geographical area. Most WANs are made from multiple LANs connected together. The internet is the largest WAN in existence.
Penetration testing (using a white hat hacker)
knowledge organisers
Malware = short for 'malicious software'. Malware can be a code or a file that is usually delivered over network. Malware has the power to infect, explore, steal or do anything an attacker wants.
Threats/attack methods
Poor network policies
SQL infections
Malware
Data interception/theft
Using people as weak points
Denial of service attacks
Phishing
Brute force attacks
Examples of malware include: worms, ransomware and trojans
Preventing network threats
Firewalls - Firewalls prevent unauthorized access to networks through the use of software. It blocks incoming and outgoing traffic based on its own set of rules
Encryption - Encryption hides data behind a key that makes it much harder to see the data, as the key has to be used to decrypt the data, therefore it protects sensitive data in transit
Multi-factor authentication - Multi-factor authentication is an authentication method that requires the user to provide two or more verification factors to gain access to a resource such as an application, online account, or a VPN.
Network security policy - A network security policy can limit security threats by defining which network assets must be protected and describing the practices and guidelines that will protect the security of these assets. They include Acceptable Use, Disaster Recovery, Back-up, Archiving and Failover policies
Social engineering
Social engineering is the term used for a broad range of malicious activities accomplished through human interactions. It uses psychological manipulation to trick users into making security mistakes or giving away sensitive information
1.5 Systems Software
1.3.2 Wired and wireless networks, protocols and layers
1.5.1 Operating systems
1.5.2 Utility system software
Network forensics - network procedures that capture, record and analyse all network events to discover the source of security attacks
Network policies
1.1 Systems Architecture
1.6 Ethical, legal, cultural and environmental impacts of digital technology
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