Blockchain Halt: When Stopping a Network Doesn't Recover Stolen Funds

Three blockchain networks - Cronos, Ontology, and ICON - halted production of blocks within four days. Each network used different emergency powers to address security concerns. The halt on Cronos resulted in the replacement of part of its canonical history after an exploit affected Tectonic.

Cronos validators halted the network by consensus and restored it to a state before the incident, resuming production from block 90,896,189. This action replaced state as well as stopping production. Transactions and state changes that existed only after the chosen restore point no longer belonged to the restarted canonical chain.

Ontology suspended block production after finding potential malicious activity during a daily check, while ICON paused an affected contract before halting the network during a migration period. The halt on ICON was implemented by the foundation-controlled network operating with a reduced core validator set.