The privacy-centric cryptocurrency Monero (XMR) has just undergone its most significant chain reorganization to date. This unprecedented event, which took place a few hours ago, resulted in an 18-block reorg and rendered 118 transactions invalid.
As reported by OrangeFren within the crypto community, users who are processing payments with XMR are now advised to wait for additional block confirmations beyond the standard ten.
Yu Xian from the blockchain security firm SlowMist likened this incident to the “sword of Damocles.” He cautioned that if the Monero community fails to acknowledge the risks associated with a reorg, it could open up vulnerabilities for double-spending attacks. Furthermore, he pointed out that achieving a 51% hash rate advantage is not always necessary for such threats.
Monero typically confirms blocks roughly every two minutes (averaging around 720 blocks daily). In its last set of 720 blocks, there were notably 108 orphaned blocks (15%) and another 103 blocks (14.31%) attributed to unknown miners—resulting in an overall orphan block rate nearing approximately 30%, significantly higher than Monero’s historical norms.
Orphaned blocks are common occurrences within Proof-of-Work systems; they arise when two miners simultaneously find a valid block. While typical rates hover between 1% and 3%, this current figure is deemed “extremely abnormal.” For context, even during August when only five out of every seven hundred twenty blocks (0.7%) were classified as orphaned was considered “unusual.” The previous Qubic situation saw this rate peak at an alarming maximum of 8.3% (60 out of every seven hundred twenty).
*This does not constitute investment advice.