An altcoin that recently suffered a 51% attack has now fallen victim to another attack. Here are the details.
Privacy-focused cryptocurrency Monero (XMR) has experienced its largest chain reorg in history. The event, which occurred hours ago, resulted in an 18-block reorg and invalidated 118 transactions.
According to a development reported by OrangeFren in the crypto community, users accepting payments with XMR are advised to wait for more block confirmations instead of the usual 10 confirmations.
Yu Xian of blockchain security firm SlowMist compared the incident to the “sword of Damocles.” He argued that if the Monero community doesn’t take the risk of a reorg seriously, the network could face the threat of double-spend. He also noted that a 51% hash rate advantage isn’t always necessary for this.
Monero confirms a block approximately every 2 minutes (an average of 720 blocks per day). In the last 720 blocks, 108 orphaned blocks (15%) and 103 blocks (14.31%) came from unknown miners, representing a total orphan block rate of approximately 30%, well above Monero’s historical average.
Orphaned blocks are a natural occurrence in Proof-of-Work systems, occurring when two miners simultaneously discover a valid block. While this rate typically ranges from 1% to 3%, the current rate is considered “extremely abnormal.” Even in August, when only 5/720 blocks (0.7%) were observed, this rate was reported as “unusual.” In the previous Qubic case, this rate reached a maximum of 8.3% (60/720).
