On June 2, 2026, the Zcash network suspended transactions in the Orchard pool due to the discovery of a critical vulnerability in its test circuit. There are no reports of exploitation of the vulnerability or loss of funds.
Thanks to coordination between developers and mining pools, the suspension was implemented in a few hours. But the mechanisms that make it possible have sparked technical debate about the true limits of decentralization in proof-of-work networks that use centralized hashrates.
Developer Jacob Gadikian explained the process of X: Zcash Open Development. Binaries to mining pool operators who invalidated Orchard transactions.
Gadikian said miners were not forced to run the new software. Each evaluated the update and decided voluntarily adoptis motivated by the interest of maintaining network survivability. According to this reading, there was no central switch or remote deactivation of the pool in the code.
However, the speed of adjustment did not depend on network structure. MiningPoolStats data for the past 1,000 blocks shows that 79% of the total hashrate was concentrated in three pools at the time of the incident: ViaBTC (36%), Foundry Digital (24%), and F2Pool (19%). its distribution Pause could be executed by simply coordinating three actors..
Analyst CyberSatoshi advocated the opposite view from Gadikian, that resisting censorship meant zero pause buttons.
According to CyberSatoshi, it is risky to call the main pool on a weekend to take down the protocol layer. Functionally equivalent to having an administrative control mechanismregardless of whether the miner acted voluntarily or not.
Technical and practical decentralization
The OrangeFren.com account summarizes the central points of discussion at X. The Orchard outage was possible because three pools control more than 78% of the hashrate. This is not a code bug, However, from the emergent properties of the actual distribution of mining power.
Zcash is a Proof-of-Work network, where miners are responsible for validating and producing blocks. When hashrate is concentrated in a small number of operators, the ability to orchestrate urgent changes to the protocol, whether it be vulnerability fixes or other interventions, is in the hands of that small group.
In this case, the arbitrariness of the process does not exclude the fact that the outcome depended on the decisions of three actors.
No losses were reported as a result of this incident. Zcash Open Development has confirmed that there is no evidence that the vulnerability has been exploited. However, according to the positions circulated in X, the ease of adjusting the pose is accurate Evidence of centralization: In a truly decentralized network, it’s impossible to have that level of coordination in that amount of time.
This incident leaves important questions open. Does a high concentration of hashrate make Zcash more vulnerable to future adjustments, whether due to emergency patches or less likely benign intervention? While this action was voluntary and intended to protect the network, it reveals Zcash’s true governance. rely on a small number of actors.
This case provides a clear lesson for other PoW networks. If the hashrate is highly concentrated, technical decentralization within the code matters little. True censorship resistance and real decentralization remain unresolved challenges in the ecosystem.
(Tag translation) Decentralization
