Basics of Cyber Technology

 The rise of cyber technology and the invention of the Internet are very important incidents in the modern technology era. With the rise of these entities, there is also an increase in cybercrimes and attacks.

Before we reach these subjects on a wider scale, we must discuss the background concepts which form the basic structure of Cyber Technology. These include topics like networking, the OSI Model, Internet, Networking protocols and some other concepts.

The OSI Model in Networks

You can imagine the internet as a giant building. The OSI model is like a blueprint for this building, dividing it into seven floors, each with a specific job.

Let's explore these floors from the bottom up −

• Physical Layer
• Data Link Layer
• Network Layer
• Transport Layer
• Session Layer
• Presentation Layer
• Application Layer

Each floor is dependent on the one below it, and together they create a smooth and efficient network. You can find more details on the OSI model from this tutorial on OSI Model

Internet and World Wide Web

Think of the Internet as the global nervous system connecting billions of devices. It's a massive network of networks, allowing everything to communicate with each other, ranging from smartphones to complex devices. This underlying entity uses complex protocols to route information efficiently. While you can send emails, transfer files, or play online games without the World Wide Web, the internet is the fundamental platform that makes these activities possible.

Built on top of the internet, the World Wide Web is the user-friendly interface we interact with daily. It's like a digital library with interconnected pages linked together by hyperlinks. This interconnectedness, often referred to as the "web," is what allows you to seamlessly jump from one piece of information to another. The web is essentially a way to access and share information over the internet.

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Internet Protocols: TCP and UDP

TCP/IP is like a postal service for the internet and all websites included in it. This is a set of rules that network nodes follow to communicate and transmit data to one another.

Within this system, there are two main methods for sending data at the transport level. These are explained in the following section −

TCP: The Reliable Service

TCP (Transmission Control Protocol) is like certified mail. It ensures that your data arrives safely and in the correct order.

UDP: The Quick Service

UDP (User Datagram Protocol) is like sending a postcard. It's fast but less reliable. It doesn't guarantee that your data will arrive or that it will arrive in the correct order.

Encryption

• Symmetric Encryption − Imagine having a single key to lock and unlock a box. This is symmetric encryption. You share the same key with whoever needs to access the information.
• Asymmetric Encryption − This is like having two keys: a public key to lock the box, and a private key to unlock it. You can share the public key widely, but only you have the private key.
• Hybrid Encryption − This is a mix of both methods. You use a fast, symmetric key to encrypt the actual data, but use asymmetric encryption to securely share that symmetric key.

Hash Functions

Hash functions are like creating a unique fingerprint for your data. No matter how small a change you make to the data, the fingerprint will be completely different each time. We use these to verify if a file has been changed or not. It is also used to store passwords securely and safely.

Digital Signatures

Digital signatures are like electronic seals on data. They verify that a message truly came from a genuine entity, and hasn't been altered on its way. This is like signing a physical document with your signature.