Cyber Security

Blockchain is a shared, immutable ledger that facilitates the process of recording transactions and tracking assets in a business network.

An asset can be tangible (a house, car, cash, land) or intangible (intellectual property, patents, copyrights, branding). Virtually anything of value can be tracked and traded on a blockchain network, reducing risk and cutting costs for all involved.

Why is blockchain important?

Business runs on information. The faster information is received and the more accurate it is, the better. Blockchain is ideal for delivering that information because it provides immediate, shared, and observable information that is stored on an immutable ledger that only permissioned network members can access. A blockchain network can track orders, payments, accounts, production and much more. And because members share a single view of the truth, you can see all details of a transaction end to end, giving you greater confidence, and new efficiencies and opportunities.

Key elements of a blockchain:

Distributed ledger technology:

All network participants have access to the distributed ledger and its immutable record of transactions. With this shared ledger, transactions are recorded only once, eliminating the duplication of effort that’s typical of traditional business networks.

Immutable records:

No participant can change or tamper with a transaction after it’s been recorded to the shared ledger. If a transaction record includes an error, a new transaction must be added to reverse the error, and both transactions are then visible.

Smart contracts:

To speed transactions, a set of rules that are called a smart contract is stored on the blockchain and run automatically. A smart contract defines conditions for corporate bond transfers, include terms for travel insurance to be paid and much more.

Benefits of blockchain:

What needs to change: Operations often waste effort on duplicate record keeping and third-party validations. Record-keeping systems can be vulnerable to fraud and cyberattacks. Limited transparency can slow data verification. And with the arrival of IoT, transaction volumes have exploded. All of this slows business, drains the bottom line, and means that we need a better way. Enter blockchain.

Greater trust:

With blockchain, as a member of a members-only network, you can rest assured that you are receiving accurate and timely data. And that your confidential blockchain records are shared only with network members to whom you granted access.

Greater security:

Consensus on data accuracy is required from all network members, and all validated transactions are immutable because they are recorded permanently. No one, not even a system administrator, can delete a transaction.

More efficiencies:

With a distributed ledger that is shared among members of a network, time-wasting record reconciliations are eliminated. And to speed transactions, a set of rules that are called a smart contract can be stored on the blockchain and run automatically.

Types of blockchain networks:

There are several ways to build a blockchain network. They can be public, private, permissioned, or built by a consortium.

Public blockchain networks:

A public blockchain is one that anyone can join and participate in, such as Bitcoin. Drawbacks might include the substantial computational power that is required, little or no privacy for transactions, and weak security. These are important considerations for enterprise use cases of blockchain.

Private blockchain networks:

A private blockchain network, similar to a public blockchain network, is a decentralized peer-to-peer network. However, one organization governs the network, controlling who is allowed to participate, run a consensus protocol and maintain the shared ledger. Depending on the use case, this can significantly boost trust and confidence between participants. A private blockchain can be run behind a corporate firewall and even be hosted on premises.

Permissioned blockchain networks:

Businesses who set up a private blockchain will generally set up a permissioned blockchain network. It is important to note that public blockchain networks can also be permissioned. This places restrictions on who is allowed to participate in the network and in what transactions. Participants need to obtain an invitation or permission to join.

Consortium blockchains:

Multiple organizations can share the responsibilities of maintaining a blockchain. These preselected organizations determine who submit transactions or access the data. A consortium blockchain is ideal for business when all participants need to be permissioned and have a shared responsibility for the blockchain.

Firewall is a network security device that observes and filters incoming and outgoing network traffic, adhering to the security policies defined by an organization. Essentially, it acts as a protective wall between a private internal network and the public Internet.

Fencing your property protects your house and keeps trespassers at bay; similarly, firewalls are used to secure a computer network. Firewalls are network security systems that prevent unauthorized access to a network. It can be a hardware or software unit that filters the incoming and outgoing traffic within a private network, according to a set of rules to spot and prevent cyberattacks.

Firewalls are used in enterprise and personal settings. They are a vital component of network security. Most operating systems have a basic built-in firewall. However, using a third-party firewall application provides better protection.

Now that we have understood what is firewall, moving forward we will see the history of firewalls.

Types of Firewalls:

A firewall can either be software or hardware. Software firewalls are programs installed on each computer, and they regulate network traffic through applications and port numbers. Meanwhile, hardware firewalls are the equipment established between the gateway and your network. Additionally, you call a firewall delivered by a cloud solution as a cloud firewall.

There are multiple types of firewalls based on their traffic filtering methods, structure, and functionality. A few of the types of firewalls are:

Packet Filtering:

A packet filtering firewall controls data flow to and from a network. It allows or blocks the data transfer based on the packet’s source address, the destination address of the packet, the application protocols to transfer the data, and so on.

Proxy Service Firewall:

This type of firewall protects the network by filtering messages at the application layer. For a specific application, a proxy firewall serves as the gateway from one network to another.

Stateful Inspection:

Such a firewall permits or blocks network traffic based on state, port, and protocol. Here, it decides filtering based on administrator-defined rules and context.

Next-Generation Firewall:

According to Gartner, Inc.’s definition, the next-generation firewall is a deep-packet inspection firewall that adds application-level inspection, intrusion prevention, and information from outside the firewall to go beyond port/protocol inspection and blocking.

Unified Threat Management (UTM) Firewall:

A UTM device generally integrates the capabilities of a stateful inspection firewall, intrusion prevention, and antivirus in a loosely linked manner. It may include additional services and, in many cases, cloud management. UTMs are designed to be simple and easy to use.

Threat-Focused NGFW:

These firewalls provide advanced threat detection and mitigation. With network and endpoint event correlation, they may detect evasive or suspicious behavior.

How Does a Firewall Work?

As mentioned previously, firewalls filter the network traffic within a private network. It analyses which traffic should be allowed or restricted based on a set of rules. Think of the firewall like a gatekeeper at your computer’s entry point which only allows trusted sources, or IP addresses, to enter your network.

A firewall welcomes only those incoming traffic that has been configured to accept. It distinguishes between good and malicious traffic and either allows or blocks specific data packets on pre-established security rules.

These rules are based on several aspects indicated by the packet data, like their source, destination, content, and so on. They block traffic coming from suspicious sources to prevent cyberattacks.

For example, the image depicted below shows how a firewall allows good traffic to pass to the user’s private network.

Why Are Firewalls Important?

Firewalls are designed with modern security techniques that are used in a wide range of applications. In the early days of the internet, networks needed to be built with new security techniques, especially in the client-server model, a central architecture of modern computing. That’s where firewalls have started to build the security for networks with varying complexities. Firewalls are known to inspect traffic and mitigate threats to the devices.

Uses of Firewalls:

Firewalls can be used in corporate as well as consumer settings.

Firewalls can incorporate a security information and event management strategy (SIEM) into cybersecurity devices concerning modern organizations and are installed at the network perimeter of organizations to guard against external threats as well as insider threats.

Firewalls can perform logging and audit functions by identifying patterns and improving rules by updating them to defend the immediate threats.

Firewalls can be used for a home network, Digital Subscriber Line (DSL), or cable modem having static IP addresses. Firewalls can easily filter traffic and can signal the user about intrusions.

They are also used for antivirus applications.

When vendors discover new threats or patches, the firewalls update the rule sets to resolve the vendor issues.

In-home devices, we can set the restrictions using Hardware/firmware firewalls.

Advantages of Using Firewalls:

Now that you have understood the types of firewalls, let us look at the advantages of using firewalls.

Firewalls play an important role in the companies for security management. Below are some of the important advantages of using firewalls.

It provides enhanced security and privacy from vulnerable services. It prevents unauthorized users from accessing a private network that is connected to the internet.

Firewalls provide faster response time and can handle more traffic loads.

A firewall allows you to easily handle and update the security protocols from a single authorized device.

It safeguards your network from phishing attacks.

Conclusion:

In this tutorial on what is a firewall, you have understood what a firewall is and how it works. You also learned the different types of firewalls and how to use a firewall. Cybersecurity is a booming field in today’s times. If you are looking to learn ethical hacking to protect devices and networks from cybercriminals. In that case, Simplilearn’s Cyber bootcamp, CEH v11 – Certified Ethical Hacking Course will help you master advanced network packet analysis and penetration testing techniques to build your network security skill-set.

Do you have any questions on this tutorial on ‘what is a firewall’? If you do, please drop them in the comments section. We will help you solve your queries at the earliest.