Difference Between DoS and DDoS Attack

The main difference between DoS and DDoS attack is that the DoS attack (Denial of Service attack) is launched by a single machine while the DDoS attack (Distributed Denial of Service attack) is launched by multiple machines.

The Internet has become a dangerous place for all organization and individuals who want to protect their data and resources. The security threats are increasing daily, and it is important to take measures to prevent them. It has become a difficult process to protect computers, networks, programs, personal details from unauthorized access. DoS attack and DDoS attack are two types of attacks hackers use to disrupt online services. These attacks cause threats to personal details and even cause financial loses to an organization.

Key Areas Covered

1. What is a DoS Attack
     – Definition, Functionality
2. What is a DDoS Attack
     – Definition, Functionality
3. What is the Difference Between DoS and DDoS Attack
     – Comparison of Key Differences

Key Terms

Botnet, DoS, DDoS, Computer Security

What is a DoS Attack

DoS stands for Denial of Service attack. The purpose of this attack is to avoid users from accessing the services provided by a website or a network. It overloads the online service, providing resources with more and more traffic.

Figure 1: Cyber Attack

Example

An example of Denial of Service is as follows: An attacker can send a large number of legitimate-looking requests to the server. The server cannot identify whether these requests are valid or non-valid. This will lead the server to come to a point at which it cannot handle the capacity any more. Likewise, this attack overloads the targeted server and disrupts the functioning of the server. Therefore, the server cannot provide services to its users further.

What is a DDoS Attack

DDoS stands for Distributed Denial of Service attack. This attack is more complicated than a DoS attack. Instead of using a single computer, it uses multiple computers. All the machines do not belong to the attacker. They are added to the network by the hacker using malware. This group of machines is called a botnet. 

The attacker develops malware and sends them to machines in the network via a controller. When a user runs it unintentionally, the machine becomes a part of the botnet. All the machines in the botnet work according to the attacker’s command and control the targeted server.

Figure 2: DDoS Attack

There are a few methods to prevent DDoS attacks. The simplest way is to use an antivirus software to protect the PCs from malware.  Furthermore, the internet service provider can also get involved to check whether the servers get legitimate requests or not. It helps to protect the client’s personal details. It is also possible to use HTTP reverse proxies as they can retrieve resources on behalf of a client from one more server.  

Difference Between DoS and DDoS Attack

Definition

The DoS attack is a cyber-attack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to the internet.  DDoS attack is a cyber-attack in which the incoming traffic flooding the victim originates from many different sources.

Stands for

DoS stands for Denial of Service. DDoS stands for Distributed Denial of Service.

Number of Machines

A single machine is used to launch a DoS attack whereas multiple machines are used to launch a DDoS attack.

Difficulty

DDoS attack is more complicated and difficult to prevent than DoS attack.  

Malware Involvement

There is no malware involvement in DoS. On the other hand, DDoS uses malware to affect multiple machines. 

Conclusion

DoS and DDoS are two types of attacks that can prevent the users from obtaining online services. The difference between DoS and DDoS attack is that the DoS attack is launched by a single machine while the DDoS attack is launched by multiple machines. In brief, DDoS attacks are more difficult to prevent than DoS attacks.

Reference:

1.“ Denial-of-Service Attack.” Wikipedia, Wikimedia Foundation, 12 July 2018, Available here.

Image Courtesy:

1. “1654734” (CC0) via Pixabay
2. “Ddos-attack-ex” – (CC BY-SA 4.0) via Privacy Canada