Understanding Network Security: Firewalls, Intrusion Detection, and Encryption

The need for maintaining network security stems from the growing reliance on digital networks for business processes, information exchange, and communication and the proliferation of cybercrimes. Malicious actors exploit networks, systems, and software vulnerabilities to gain unauthorized access to sensitive data or disrupt business operations.

The effects of cyberattacks can be ravaging, resulting in data breaches, financial loss, and identity theft. Statistics show that cybercrime is expected to cost organizations globally $10.5 trillion in a year by 2025. Cybersecurity measures are therefore important to secure networks from such threats.

In this post, we’ll explore three key cybersecurity measures, including firewalls, intrusion detection, and encryption, and how they function to enhance network security.

Firewalls: The First Line of Defense

A firewall is a network security device that, along with reliable antivirus software, analyzes incoming traffic based on pre-established security policies and filters traffic coming from suspicious sources to prevent cyberattacks. Essentially, it builds a barrier between a private internal network and a public network from external sources to prevent malicious software from entering the devices or network.

Types of Firewalls

• Host-based Firewall - This application controls incoming and outgoing data packets to protect hosts from attacks and unauthorized access.

• Network-based Firewall - This type of firewall is a dedicated system that works on the network level by using two or more network interface cards (NICs). Over the years, it has been further divided into different types to play significant roles in network security. These include packet-filtering firewalls, circuit-filtering firewalls, application gateway firewalls, stateful firewalls, and next-generation firewalls.

How Does A Firewall Work

A firewall works by distinguishing between good and malicious web traffic and allowing or blocking specific data packets based on predefined security rules. These rules are based on different aspects the data packets indicate, like their source, destination, content, etc. Some firewalls can also track audit logs to find connections and web traffic that have gotten through.

Benefits of Firewalls

Some important advantages of using firewalls are as follows:

• Firewalls can record and monitor all network traffic to help identify and look into security problems.

• Users can control entry points in a system and thwart virus attacks using firewalls.

• A firewall enables users to easily handle and update the security protocols from one authorized device.

• It helps promote privacy by proactively working to keep data secure.

Intrusion Detection System: A Second Layer of Security

An intrusion detection system (IDS) is a system that monitors inbound and outbound network traffic and devices for suspicious activities or security policy violations and issues alerts about them. It enables real-time intrusion detection to detect anomalous patterns within a network or system.

Types of Intrusion Detection Systems

Out of an extensive range of IDS, here are the most common classifications:

• Network-based Intrusion Detection Systems (NIDS) - This system tracks and analyzes incoming and outgoing network traffic and identifies threats or suspicious activities.

• Host-based Intrusion Detection Systems (HIDS) - It operates from a certain endpoint, scanning network traffic and operating files to and from one device.

How Does An IDS Work

IDS uses a database of known system vulnerabilities or information related to deviations from network activities to find abnormal patterns. The system then sends these anomalies for review and assessment at the application layer.

Three different components help manage IDS's internal working, such as sensors, a console, and a detection engine. Additionally, the IDS uses 3 different approaches to detect malicious traffic, which are as follows:

• Signature Detection - It tracks packets passing through a network and contrasts them with a database of known attack signatures or attributes to issue alerts. This method looks for specific patterns, such as the number of bytes or instruction sequences.

• Anomaly Detection - This detection method creates a baseline model of normal network activities and compares future activities to the model to label any anomalies as potential threats and generate alerts.

• Hybrid Detection - It uses both signature and anomaly detection methods to detect more potential threats with a minimum error rate.

Advantages of IDS

Some of the main advantages of using IDS are as follows:

• It detects suspicious activities and notifies the system administrator to prevent substantial damage.

• It provides meaningful insights into network traffic for improving security.

• The system aids companies in meeting compliance requirements to ensure adherence to related rules and regulations.

Encryption: Protection Against Unauthorized Access

Encryption is a computing process used to convert human-readable data into encrypted data that is accessible only by authorized users having the right cryptographic key (a set of mathematical values that both the sender and receiver of an encrypted message agree on). It is foundational to cybersecurity because it can provide authentication, integrity, confidentiality, and non-repudiation.

Types of Encryption

Depending on the number of encryption keys used, below are the two main encryption types:

• Symmetric - Symmetric encryption, or private key encryption, uses the same key for encryption and decryption. It consumes less money and computing power than asymmetric encryption. DES, 3DES, AES, Blowfish, and Twofish are the most widely used symmetric encryption ciphers.

• Asymmetric - Also called public key encryption, asymmetric encryption uses two distinct keys (public and private) to encrypt and decrypt data. This type of encryption is a foundational technology for TLS/SSL. Some common asymmetric encryption ciphers include RSA, ECC, and PKI.

How Does Encryption Work

Encryption takes plain text and scrambles into an incomprehensible format called ciphertext. When the recipient receives the message from the sender, the information is translated back to its actual form using a secret key.

Pros of Encryption

Encryption is important for the following reasons:

• Encryption solutions support data integrity by allowing only authorized access to information.

• It ensures files on the internal storage hub or uploaded to the cloud are safe from data loss or theft.

• There is a stable network connection to prevent packet loss.

• It prevents attackers, ISPs, and governments from reading sensitive user data.

Summary

Managing and securing the network is crucial for protecting digital assets from cyber-attacks and unauthorized access. With the robust trio of firewalls, intrusion detection, and encryption, companies and individuals can mitigate the risk of online threats and build a safe digital environment.