The Cache Was Warm, The Bitcoin Was Real: A $320M Heist on the Liquid Network
On September 6, the Liquid Network accepted a transaction whose confidential L-BTC output rested on an invalid rangeproof. Two ordinary peg-out requests followed through SideSwap, and functionary watchmen paid out 3,998.67 BTC from the real Bitcoin reserve. In a comprehensive post-mortem, Max dissected the root cause: The defect was a cache key that recorded less than the verifier had checked
. Elements had introduced rangeproof caching in March 2019, but for seven years the implementation indexed cache entries by proof and value commitment alone, omitting asset generators and script context. In Max’s words, Three controls failed and only one of them was mathematical
, and For seven years … filed the answer to a four-part question under a two-part label.
A six-line fix had actually been committed to the public Elements repository on September 1 as part of a routine maintenance bundle without an accompanying security advisory or emergency release tag. Once on-chain exploiters seized the funds, they broadcast messages onto the Bitcoin blockchain asserting they were whitehats and asking to negotiate terms. Cryptographer waxwing asked rhetorically: Why the heck wouldn't they belt and suspenders with the transaction hash?
Meanwhile, veteran Bitcoin core developer Matt Corallo pushed back forcefully against the benign framing: Finally, they kept 15%? That’s not even remotely white hat behavior. They just wanted to use the term “whitehat” to reduce risk of FBI.
Community observers noted that negotiating a ~600 BTC retained balance—over $50 million—represents an unprecedented extraction. Alan Siefert observed: They essentially negotiated to have Blockstream publicly say the transaction is some amount of consensual rather than pure theft in hope that law enforcement doesn’t act.
Bull Bitcoin CEO Adam O’Brien was equally blunt: They’re negotiating ransom White hats have stains
. With functionaries halting block production and disabling ingress, platforms across the ecosystem were forced to freeze operations.
Further reading: Read Max’s technical dissection · Matt Corallo on the ransom · Hodl Hodl announcement.
