Denial-of-Service (DoS) Attack

Understanding Denial-of-Service (DoS) Attacks

A Denial-of-Service (DoS) attack is an act that aims to limit access to a computer or network, preventing legitimate users from using it. Hackers often use DoS attacks to disrupt the normal functioning of computer-based services. One effective way to carry out such an attack is through a distributed method.

Denial-of-service attacks can take different forms and have different organizational structures. Volumetric attacks involve overwhelming a network by flooding it with echo requests, using up its entire bandwidth capacity. Syn flooding attacks are similar, but the attacker rapidly initiates connections to a server without completing them. Fragmentation attacks disrupt the target network’s ability to reassemble data packets. Application layer attacks exploit undetected programming errors in an application or network by overwhelming the target with requests. Lastly, phlashing DoS attacks aim to permanently damage the target network by sending false update requests and inserting malware throughout the network.

Distributed denial-of-service (DDoS) attacks are the most common type of malware attack. In a DDoS attack, hackers introduce malware to networks of connected devices and bombard them with a massive volume of requests, overwhelming the network.

Unfortunately, cryptocurrency exchanges have increasingly become targets of DDoS attacks due to their growing popularity. Since 2020, major crypto exchanges have experienced numerous attempts at DDoS attacks, resulting in prolonged unavailability of their services.

With the rise of blockchain technology applications, a new type of DoS attack has emerged known as a blockchain denial-of-service (BDoS) attack. These attacks specifically target blockchains that operate under the proof-of-work (PoW) consensus mechanism, such as Bitcoin.

In a BDoS attack, the focus is on disrupting the rewards mechanism for miners. The PoW consensus mechanism relies on miners to validate new blocks, and if miners do not receive their rewards, the block validation process is interrupted. It is important to note that successfully executing a DoS attack on a decentralized network, like blockchain-based networks, is significantly more challenging. Traditional DoS attacks exploit the centralized nature of networks, which does not apply to decentralized networks. To interrupt the mining process in a blockchain network, attackers send fake proofs to the blockchain, claiming to have a mining advantage. This discourages other miners from performing the necessary operations for transaction validation, significantly slowing down the processing power of the blockchain. However, BDoS attacks have been extremely rare and unsuccessful thus far.