Japan’s Liquid Global exchange said it has been hacked, and has suspended deposits and withdrawals.
According to a tweet on Thursday, the exchange said its warm wallets were compromised and that it was moving digital assets offline.
While the total amount stolen has yet to be determined, the value taken in bitcoin, ether, ripple, tron, and others could be upward of $90 million, Eddie Wang, senior researcher at OKLink, told CoinDesk.
“We are currently investigating and will provide regular updates,” the exchange said in the tweet. “In the meantime, deposits and withdrawals will be suspended.”
In a later tweet, Liquid Global said it’s working with other exchanges to freeze the funds.
Crypto exchange KuCoin’s CEO, Johnny Lyu, said his platform was aware of the incident and had blacklisted the hacker’s wallet addresses. Other exchanges are likely to follow suit.
So far, it has revealed nine wallet addresses where the hacker is depositing heisted funds.
One of the addresses Liquid Global revealed was still receiving bitcoin at 7:20 UTC
In a blog post on the incident, translated from the Japanese by Google, Liquid Global claimed the hack targeted a multi-party computation (MPC) wallet. “This time, the MPC wallet (used for warehousing / delivery management of cryptographic assets) used by our Singapore subsidiary QUOINE PTE was damaged by hacking.” the company said.
MPC is an advanced cryptographic technique in which the private key controlling funds is generated collectively by a set of parties, none of whom can see the fragments calculated by the others. Liquid Global’s blog post did not explain how this security arrangement was circumvented.
Liquid Global is unrelated to the Liquid Network, the sidechain, or parallel system, to Bitcoin created by tech startup Blockstream.
UPDATE (AUG. 19, 7:59 UTC): Adds Liquid Global is working with other exchanges; updates number of destination addresses.
UPDATE (AUG. 19, 8:37 UTC): Updates value taken.
UPDATE (AUG. 19, 13:45 UTC): Adds detail from Liquid Global’s explanation of hack.