Why Harvard Research on a Low-Profit Tezos Attack Matters for Proof-of-Stake

Published on by Coindesk | Published on

A recent academic study says Tezos is threatened by "Selfish mining," providing a valid threat model for other live and up-and-coming proof-of-stake cryptocurrencies.

That's the finding from Selfish Behavior in the Tezos Proof-of-Stake Protocol, published last November by then-Harvard researcher and current Google engineering intern Michael Neuder.

The paper from Neuder and other Harvard researchers shows the profitability - albeit small - of "Selfish endorsing" attacks in Tezos, a variant of selfish mining.

"It was a great research paper and we'd love to see more focus on economic and complex-system-interactions in cryptocurrency systems in academic and industrial research," Tezos Chief Security Officer Ryan Lackey told CoinDesk in an email.

As described and proven by the researchers, a Tezos baker can be rationally incentivized to create their own blocks and receive endorsements from other bakers not connected to the main chain, creating a secondary invalid chain.

The attack may be unlikely due to the high costs, but Tezos is still taking the issue seriously.

An ongoing election is expected to pass a network upgrade altering endorsement incentives, according to Adrian Brink of Tezos blockchain research firm Cryptium Labs."It's important to understand that most of these attacks are not short-term dangers but rather long-term dangers, since they are obvious if executed and only start to have a serious impact if executed over months to years," Brink said via email.

Network attack vectors such as selfish mining highlight Tezos' on-chain governance and the ability to address headaches before they become migraines.

Compared to other chains, Tezos has taken the unexplored path when it comes to large-cap coins requiring censorship-resistance and stability.

"I think Tezos has done well in that respect," Carter said.

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