Fight fire with fire: MIT scholar suggests ETC counters 51% attacks

Not only has ETC been attacked three times within a month, but these assaults have been enabled with rented hashrate power.

He co-authored a recent paper on defending against "Double-spend" attacks with Neha Narula, director of MIT Media Lab's Digital Currency Initiative, and Daniel Moroz, Ph.D. candidate in computer science at Harvard University - both of whom provided input in Aronoff's correspondence with Cointelegraph.

"Our work on blockchain incentives shows that theoretically a deep-pocketed exchange can deter double-spend attacks if potential attackers believe the intended victim will counter-attack and negate the attempted double-spend."

Intuitively, the exchange and the attacker are fighting over the value of the current double-spend attack, he noted, "But the exchange also risks encouraging more attacks in the future if it allows the attack to succeed. Therefore, the exchange has more to gain by defeating the attack than does the attacker have to gain by succeeding."

The model shows that the mere threat of this kind of counterattack eventually "Induces a subgame perfect equilibrium in which no attack occurs in the first place." Meanwhile, in the real world, attacks on networks like ETC continue.

In the aftermath of the attack, ETC called for enforcement and regulation of hash-rate rental platforms.

Emin Gün Sirer, CEO of Ava Labs and associate professor of computer science at Cornell University, told Cointelegraph that ETC's case wasn't unique: "Any PoW coin that isn't the leader in its hash function is vulnerable to attacks such as these." He went on to add: "Their security relies on the amount of hashpower that an attacker can get their hands on, and as that number grows, the number of confirmations required for security goes towards infinity."

On Sept. 4, Charles Hoskinson's IOHK proposed to the ETC community that it use Cardano or Bitcoin networks to prevent 51% attacks.

A better long-term solution in Sirer's view would be to switch to a different consensus protocol - one that isn't vulnerable to 51% attacks, which would "Allow ETC to be minted with existing miner infrastructure, while computing the checkpoints in a decentralized fashion, without trusted keys or community members."

The OKEx CEO also put forth a warning: "It's imperative that ETC fix the vulnerabilities in the network that make the possibility of another attack in the short-term high, as they could place ETC's future at risk and/or cause exchanges like OKEx to delist."