Study questions Bitcoin loss

According to a Swiss study, fewer than 400 bitcoins could have been stolen from the Mt. Gox Bitcoin exchange using so-called transaction malleability attacks.





The findings by Christian Decker and Roger Wattenhofer of the Distributed Computing Group at the Swiss Federal Institute of Technology Zurich (ETH) cast doubt on the explanation of how MtGox lost nearly half a billion dollars’ worth of the digital currency.

the authors write: “In this work we use traces of the Bitcoin network for over a year preceding the filing to show that, while the problem is real, there was no widespread use of malleability attacks before the closure of MtGox.”

In their study, the ETH researchers found that only 302,700 bitcoins were involved in malleability attacks.

“Of these, only 1,811 bitcoins were in attacks before MtGox stopped users from withdrawing bitcoins,” they wrote. “Even more, 78.64 percent of these attacks were ineffective. As such, barely 386 bitcoins could have been stolen using malleability attacks from MtGox or from other businesses. Even if all of these attacks were targeted against MtGox, MtGox needs to explain the whereabouts of 849,600 bitcoins.”