The current blockchain reorganization through which networks discard blocks and monitor lengthy chains revealed weaknesses within the Proof of Work (POW) system highlighted by Monero’s August 2025 ordeal and former disruptions throughout different blockchains.
Decode the chain
A blockchain reorganization, or Reorg, happens when a sequence of blocks is deserted in favor of a aggressive model with a bigger cumulative proof (POW), successfully rewrites a portion of the ledger. Reorgs rolls again transactions on orphaned blocks, sends them again to Mempool and sends them again to exclude exclusions.
This enables the attacker to spend cash on the discarded chain, however can nonetheless be held after a reorganization. In August 2025, Monero endured repeated Reorgs tied to the Qubic Mining Pool, which collected a dominant share of the hashrate. Qubic publicly described this effort as an experiment, utilizing the Pow setup to mine Monero blocks and declare rewards.
Picture supply: Vini Barbosa. X Account Vini Barbosa reported that Monero had breeded two 9 blocks inside 60 minutes from blocks 3485726→3485734 to 3485708→3485716.
Its energy first enabled a 6-block roll and confirmed how the ledger may very well be rewritten. A number of extra later, two lately reported 9 blocks of Leorg had been carried out. Monero’s Reorgs originated from Qubic’s wonderful hashrate, permitting non-public mining of lengthy chains and compelled nodes earlier than revealing it. Dangers embrace double spending, transaction censorship, and complications for erased blocks.
Exchanges like Kraken Susped Deposits later requested a affirmation of 720, exceeding the traditional 10, stopping losses. The confusion sparked debate by revamping the Monero consensus, suggesting that from merge mining with Bitcoin to geographically distributed {hardware}, it weakened a big pool and led to sprint chain locks the place the masternode blocks lock blocks.
In August 2021, Bitcoin SV confronted related checks when unknown miners managed greater than half the hashrate and pulled out a large 100 block of reported röorg. The occasion break up the chain into three variations, giving it credibility. The trigger comes from stealth miners who construct hidden chains, resulting in acquainted dangers: double spending, instability, and shaking self-confidence.
Reorgs emphasizes the stochastic finality of Pow. Transactions are safer with further confirmations, however a 51% benefit can override them. Each episodes reveal Reorgs as a pure correction software that twists the assault technique, facilitating the decision to extra highly effective decentralization and hybrid safety.
The Monero and BSV expertise reveals the duality of Reorgs, which, in wholesome operations, is devastating when weaponized.
Bitcoin (BTC) is far more costly to assault as a result of it has a really excessive hashrate benefit in comparison with different POW blockchains. The community runs on tons of of exhash (EH/S) per second with globally distributed mining farms working specialised ASIC {hardware}.
To reorganize the Bitcoin chain, attackers should secretly marshall most of their hashrate. This can be a feat that requires billions of {dollars} for mining rigs, industrial-scale infrastructure and massive quantities of electrical energy. The required stage of funding makes such an try economically irrational.
Monero (XMR) and Bitcoin SV (BSV) are less expensive to assault because the POW system operates at a few of the Bitcoin hashrates and the mining entrance prices are dramatically decrease.
