Vertcoin experiences another major blockchain reorganization

Historical retrospective compiled on 24 October 2026. Dated to the attack on 1 December 2019; technical analysis followed afterward.

Evidence: Original researcher investigation.

Researcher James Lovejoy documented a Vertcoin attack in which 603 main-chain blocks were removed and replaced by 553 attacker blocks on 1 December 2019. After being alerted, Bittrex disabled its Vertcoin wallet. The analysis identified five double-spent outputs totaling approximately 125 VTC, while explaining uncertainty about the attacker’s purpose and whether a larger exchange-directed double spend had been intended. The incident should therefore not be described as a proven large exchange theft merely because the reorganization was deep. It provided unusually detailed public evidence about the use of rented mining power and the practical response of an exchange.

Sources: James Lovejoy’s original analysis; MIT research project.