Ethereum network hit by computational DDoS attack

Ethereum, a public blockchain-based decentralised computing platform for the cryptocurrency Ether, is currently undergoing a Distributed Denial of Service (DDoS) attack on its network, causing all mining activities to slow down.

Ethereum co-founder Jeffrey Wilcke posted an alert on the official Ethereum blog at around 4pm BST on 22 September, warning miners that the network was suffering from a computational DDoS that was causing both miners and nodes to spend a very long time processing some blocks.

In a regular DDoS attack, a sustained flood of traffic is sent to the victim's network to try to overload the servers and take the network offline. In contrast, a computational DDoS attack works by picking a cryptographic process that the server is trying to perform, such as a handshake phase when encryption keys are being exchanged to authenticate a connection.

The attacker demands that the server repeatedly compute the same process again and again, until the server is unable to keep up with computing all the requests. This is what is happening to the Ethereum network – attack transactions are currently repeatedly calling an opcode called "EXTCODESIZE" about 50,000 times per block, which slows down all legitimate mining operations.

"The consequence of this is that the network is greatly slowing down, but there is no consensus failure or memory overload. We have currently identified several routes for a more sustainable medium-term fix and have developers working on implementation," Wilcke wrote in the blog, stressing that no nodes have crashed.

The Ethereum team is currently fixing the problem and looking at solutions to prevent it happening in the future, but in the meantime, Ethereum miners are highly encouraged to switch over to Parity mining using the following settings:

Ethereum is rising up the ranks in popularity as a cryptocurrency, and recently received endorsement from Spanish banking giant Santander, which has created a way to tie its bank accounts and fiat currency to tokens on the Turing complete blockchain system.

Santander wants to offer banking customers the opportunity to set up a parallel Ethereum account from their Santander online banking accounts, which can be used for a variety of purposes, including as a micropayment to pay for online services like paywalled newspaper articles.