Monero Eyes ‘Detective Mining’ Defense After Qubic Attack
Monero (XMR) builders and pool operators are weighing a swift, software-level response to final week’s hashrate shock after the Qubic mining pool claimed it had briefly dominated the community and triggered a six-block reorganization. Former Monero lead maintainer Riccardo Spagni proposed deploying “detective mining,” a pool-side technique he says can neutralize selfish-mining assaults with no laborious fork. “A proposal to make Monero fully resilient to selfish-mining assaults, no protocol adjustments wanted,” Spagni wrote, linking to a brand new Monero Analysis Lab problem that outlines the method.
Qubic’s marketing campaign culminated on Aug. 12 with public statements that it had surpassed 51% of Monero’s hashrate and “efficiently reorganiz[ed] the blockchain,” a part of what the mission billed as a dwell “51% takeover demo.” Qubic itself characterised its technique as “egocentric mining,” a tactic that may win outsized rewards with as little as “33–40%” of hashrate, not essentially a full majority.
Threat controls kicked in throughout the business. Kraken posted a status notice in mid-August that it had paused XMR deposits “after detecting {that a} single mining pool has gained greater than 50% of the community’s complete hashing energy,” holding buying and selling and withdrawals open whereas it monitored community integrity. The pause underscored how even short-lived reorganizations—Monero targets two-minute blocks, making six blocks roughly twelve minutes—can pressure exchanges to reassess affirmation insurance policies.
Not everybody accepted Qubic’s framing. Analysts on the RIAT Institute argued “no 51% assault has occurred,” citing knowledge suggesting Qubic’s peak contributed far lower than a real majority and noting {that a} six-block reorg is inadequate proof of sustained management able to reversing absolutely confirmed transactions.
Detective Mining Might Protect Monero
Spagni’s “detective mining” proposal seeks to break down the benefit of any pool making an attempt egocentric mining by exploiting data already uncovered in pool job messages. In pooled mining, Stratum job payloads embrace the earlier block hash (“prevhash”). A detective miner (or a pool operating a “sensor” proxy) subscribes to competing swimming pools’ job streams; when a leaked prevhash doesn’t match the general public tip, the pool instantly builds and broadcasts a sound youngster on high of the attacker’s hidden dad or mum, forcing the egocentric miner to disclose or lose its personal lead. As a result of this operates solely on the pool/Stratum-proxy layer, it requires “no consensus or protocol adjustments,” making it deployable on in the present day’s Monero stack.
The economics are the purpose. Spagni’s abstract of the underlying Lee–Kim mannequin (2019) claims that if roughly half of community hashrate (i.e., the biggest swimming pools) undertake detective mining, the egocentric miner’s break-even threshold jumps into the ~32–42% vary relying on tie-breaking assumptions—eroding the assault’s profitability and, with wider adoption, wiping it out throughout examined splits. That could be a materially larger hurdle than the classical Eyal–Sirer outcome, beneath which egocentric mining will be worthwhile round one-quarter to one-third of hashrate.
Spagni’s problem additionally anticipates adversarial counter-moves. It recommends quorum-based detection from a number of sensors, brief “grace home windows” earlier than diverting hashrate, and share-submission checks to defeat decoy jobs—all with charge limits and telemetry to tune false-positive danger. These are pragmatic pool-operator playbooks fairly than protocol-level guidelines, aligning with Monero’s desire to harden incentives and operations earlier than touching consensus.
For Monero, the following steps can be social as a lot as technical: main swimming pools would wish to ship and allow detective-mining logic for the protection to chew on the modeled thresholds. As of Aug. 19, the concept is a public proposal beneath lively dialogue fairly than an adopted normal. However after per week during which a single pool’s marketing campaign produced a measurable reorg and exchange-level mitigations, the trail of least friction—pool software program updates that increase the price of egocentric mining—has shortly grow to be the middle of gravity for the mission’s short-term response.
At press time, XMR traded at $268.
