Linea, an Ethereum Layer 2 blockchain, deliberately paused its block production in response to a security exploit on Velocore, a decentralized exchange on the network. The hack resulted in an unauthorized withdrawal of over $7 million in ether on June 2. To prevent further damage, Linea took decisive action, halting block production by pausing the sequencer and censoring attacker addresses. This move was made to safeguard users and builders within the ecosystem.

Linea's decision to pause the sequencer was driven by the hacker's acquisition and attempted sale of a large sum of tokens into ether. The sequencer was paused from block 5081800 and 5081801, according to Linea. This incident and Linea's response sparked comments from industry figures, including Matter Labs' CEO Alex Gluchowski, who emphasized the urgency for Layer 2 networks to prioritize decentralization.

Gluchowski, who leads the development of zkSync, a competitor to Linea, stressed that decentralizing the sequencer is not optional and that every serious Layer 2 stack must make it a priority. Linea acknowledged that its network is still in a "training wheels" phase, indicating centralization, but reaffirmed its commitment to actively moving towards a decentralized model. This decentralized environment would prevent unilateral actions by core developers from halting the chain.

Linea's product lead, Declan Fox, reiterated the project's commitment to quickly decentralizing the network, stating that Linea is on a solid path to decentralizing all aspects of the network in an aggressive time window. Decentralizing the sequencer would enable sequencer nodes from multiple parties to order and batch transactions on Layer 2 and submit them to the Ethereum base chain, avoiding a central point of failure and ensuring fairness in block sequencing.

While rollups offer a promising solution for scaling Ethereum dApps, they inherently introduce centralization risks due to reliance on sequencers controlled by project teams. This setup presents single points of failure and potential censorship issues. Decentralizing this infrastructure is crucial, and most Layer 2 chains, including Linea, plan to achieve this in the future.

Despite the move towards decentralization, the practice of halting entire blockchains to prevent hackers from transferring funds remains widespread across the industry, even among Layer 1 networks considered relatively more decentralized than Layer 2s. Historically, developers at BNB Chain, Osmosis, and Acala have halted their respective chains and censored perpetrators' accounts following large security exploits, working with their respective validators.

Linea's commitment to decentralization is a step in the right direction, and its decision to pause block production to protect its ecosystem demonstrates its dedication to prioritizing user security. As the industry continues to evolve, it is essential for projects like Linea to prioritize decentralization and work towards creating a more robust and secure ecosystem for all users.