How DDoS attacks work and why they threaten cryptocurrency networks

In the era of digital transformation, the security of online infrastructure is becoming increasingly critical. Among the most insidious threats are DDoS attacks, which can temporarily disable even large global services. While the origins of these cyber incidents date back to 2000, when a fifteen-year-old Canadian teenager attacked the servers of companies like Amazon and eBay, their frequency and sophistication have significantly increased since then.

What exactly does a DoS attack mean and how does it differ from DDoS

DoS Attack (Denial-of-Service) represents an attempt to enforce the non-functionality of the target server or web resource. The basic principle lies in overloading the system with an excessive volume of data or malicious requests that individual network elements cannot process. The duration of such an attack ranges from minutes to several days in extreme cases.

However, a more significant difference is the category DDoS (Distributed Denial-of-Service) attack. While a DoS attack comes from a single computer or source, a DDoS attack coordinates thousands of compromised devices. This makes the attack much more effective and harder to trace its origin. Cyber delinquents therefore prefer DDoS attacks, as their initiators are very difficult to track down.

Typical ways of carrying out such attacks

The most common type is a cache flooding attack. Here, the attacker sends a drastically larger volume of traffic than the system was designed to handle. The result is often a complete failure of the target process.

Another common approach is flooding ICMP packets. This method exploits poorly configured devices in the network, which instead of responding to a single node, send data to all nodes at once. This scenario is colloquially known as “ping of death” or “smurf attack.”

A more technically sophisticated method is the flooding of SYN packets. The attacker initiates false connection requests here but never confirms them. All open ports of the target server are thus exhausted on invalid connection attempts.

Impact on Cryptocurrency Infrastructures and Their Resilience

Cryptocurrency exchanges have become more attractive targets for DDoS attacks in recent years. An emblematic example was the massive attack on the Bitcoin Gold network shortly after its launch, which took services offline for several hours.

However, blockchain technology has significant inherent protection. Its decentralized architecture means that the failure of several nodes does not jeopardize the functioning of the entire network. Even if some components are offline or under attack, the remaining nodes continue to verify transactions. Once the damaged nodes reconnect, they synchronize with the latest data from the healthy parts of the network.

The resilience of a blockchain network directly correlates with the number of active nodes and the overall hashrate. Bitcoin, as the oldest and largest digital asset, represents the pinnacle of openness to these threats. The proof-of-work consensus mechanism provides a cryptographic guarantee of the integrity of all transactions. Modifying historical data would require recalculating the entire chain block by block, which is practically impossible even with the most powerful current technology.

Theoretically, a DDoS attack combined with a 51% majority attack could briefly affect the last few blocks. However, the community itself would respond very quickly to such a scenario by updating the protocol, making the attack economically unprofitable.

In conclusion, it can be said that while DDoS attacks pose a serious threat to centralized systems, blockchain technology has a robust defense mechanism against them.