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1)Networking Components:
- i)Switches:
- Switches are used to connect various devices simultaneously
- It works in data link layer
- switches are cheaper than Routers
- ii)Routers:
- Routers are used to connect various networks simultaneously
- It works in Network Layer
- Routers are expensive than switches
- iii)Hub:
- Hub is a Hardware device used to connect multiple devices in the Network
- It works in Physical Layer
- iv)Client:
- Devices used by the people to access the Network Services
- V)Server:
- Client access the resources from the servers
2)Benefits of Networks:
- i)Resource Sharing:
- Multiple users share files, Hardware and Software Applications easily
- It reduces the duplication of resources
- ii)Scalability:
- New devices and users can be added easily
- iii)Availability and Reliability:
- It stores duplicate copies of data
- In case of Failure, the data is still safe which makes it more reliable and highly available
- iv)Cost Effectiveness:
- Sharing the Resources reduces the equipment cost
- V)Communication:
- It allows users to communicate by using emails, messages, etc...
3)OSI Model:
- OSI stands for Open System Interconnection
- The OSI Model consists of 7 Layers
- Physical Layer
- Data Link Layer
- Network Layer
- Transport Layer
- Session Layer
- Presentation Layer
- Application Layer
- i) Physical Layer:
- Physical Layer is Layer 1 in the OSI Model
- It is responsible for the physical connection between the devices.
- ii) Data Link Layer:
- Data Link Layer is Layer 2 in the OSI Model
- It is responsible for the node-to-node transmission of data
- iii) Network Layer:
- Network Layer is Layer 3 in the OSI Model
- It is responsible for the host-to-host transmission of data
- iv) Transport Layer:
- Transport Layer is Layer 4 in the OSI Model
- It is responsible for the end-to-end transmission of data
- v) Session Layer:
- Session Layer is Layer 5 in the OSI Model
- It is responsible for establishing, managing and terminating the sessions
- vi) Presentation Layer:
- Presentation Layer is Layer 6 in the OSI Model
- Presentation Layer is also called the Transition Layer
- vii) Application Layer:
- Application Layer is Layer 7 in the OSI Model
- Application creates the data
4)TCP/IP Model:
- TCP/IP stands for Transmission Control Protocol/Internet Protocol
- The TCP/IP Model consists of 4 Layers
- Physical Layer
- Data Link Layer
- Network Layer
- Transport Layer
- Application Layer
- i) Physical Layer:
- Physical Layer is Layer 1 in the TCP/IP Model
- It is responsible for the physical connection between the devices.
- ii) Data Link Layer:
- Data Link Layer is Layer 2 in the TCP/IP Model
- It is responsible for the node-to-node transmission of data
- iii) Network Layer:
- Network Layer is Layer 3 in the TCP/IP Model
- It is responsible for the host-to-host transmission of data
- iv)Transport Layer:
- Transport Layer is Layer 4 in the TCP/IP Model
- It is responsible for the end-to-end transmission of data
- v) Application Layer:
- Application Layer is Layer 5 in the TCP/IP Model
- Application creates the data
5)Elements of Cybersecurity:
- Cybersecurity refers to the protection of data from unauthorized access and cyberattacks
- The main goal of cybersecurity is to provide the CIA
- C stands for Confidentiality
- I stands for Integrity
- A stands for Availability
- a)Information Security:
- It protects the data during sending and storing from unauthorized access and cyberattacks
- It ensures the CIA
- b)Network Security:
- It protects the Network Infrastructure from unauthorized access and cyberattacks
- It ensures secure data transmission between sender and receiver
- c)Application Security:
- It protects the Software Applications from unauthorized access and cyberattacks
- d)OPSEC:
- OPSEC stands for Operational Security
- It protects the sensitive Information from unauthorized access and cyberattacks
- e)Cloud Security:
- It protects the cloud-based resources and data from unauthorized access and cyberattacks
6)Cyber Security Services and Objectives:
- a)Confidentiality:
- Confidentiality refers to hiding the information from unauthorized access during exchange
- b)Data Integrity:
- Data Integrity prevents unauthorized modifications to the Information
- Data Integrity also detects the modifications made
- c)Availability:
- Data must be easily available to the authorized users
- d)Authentication:
- Authentication is used to verify the identity of a user or device
- There are mainly two types of Authentication
- i)Peer-Entity Authentication
- ii)Data-Origin Authentication
- e)Non-Repudiation:
- Non-Repudiation prevents the denial of message transmission between sender and receiver
7)Security attacks:
- The attempt that breaks the security of organization information
- Security attacks are mainly categorized into two types:
- i)passive attacks
- ii)active attacks
- i)Passive attacks:
- In passive attacks, it gathers the information without altering the system
- Passive attacks are mainly categorized into two types:
- a)Release of Message Contents
- b)Traffic Analysis
- ii)Active attacks:
- In Active attacks, it gathers the information by altering the system
- Active Attacks are mainly categorized into four types:
- a)Masquerade
- b)replay
- c)Modifications of messages
- d)Denial of Service
- Other Security Attacks:
- i)Malware:
- It is a software designed to harm the system
- It is spread via emails, messages, websites, etc...
- Malware does not necessarily require the user to spread
- ii)Spyware:
- It is a type of Malware designed to steal information secretly
- It is spread by installing harmful programs
- Spyware requires the user to spread
- iii)Worm:
- It is a type of Malware designed to damage the information
- It is spread automatically by network connection
- Worm does not require the user to spread
8)Recent security attacks:
- Uber Data 2016:
- Hackers stole 57 million Uber users' personal data in 2016
- Uber accidentally uploaded login details to GitHub
- Hackers stole the data from third-party cloud servers
- Bangladesh Bank Heist 2016:
- Hackers broke into the Bangladesh Bank's system and tried to steal money by sending a fake transfer request
- They sent a fake Swift message to the bank and successfully transferred 101 million from the bank
- Indian Debit Card 2016:
- Around 3.2 million debit cards were hacked in India
- Several Banks, SBI, HDFC, ICICI, Axis, and Yes Bank are affected by this
- Here, malware was injected into ATM/POS Systems
- BSE 2025:
- BSE stands for Bombay Stock Exchange
- They warned the companies to be careful that the hackers from Pakistan are trying to attack India's Banking and Financial Systems
