'$300m in cryptocurrency' accidentally lost forever due to bug

More than $300m of cryptocurrency has been lost after a series of bugs in a popular digital wallet service led one curious developer to accidentally take control of and then lock up the funds, according to reports.

Unlike most cryptocurrency hacks, however, the money wasn’t deliberately taken: it was effectively destroyed by accident. The lost money was in the form of Ether, the tradable currency that fuels the Ethereum distributed app platform, and was kept in digital multi-signature wallets built by a developer called Parity. These wallets require more than one user to enter their key before funds can be transferred.

On Tuesday Parity revealed that, while fixing a bug that let hackers steal $32m out of few multi-signature wallets, it had inadvertently left a second flaw in its systems that allowed one user to become the sole owner of every single multi-signature wallet.

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The user, “devops199”, triggered the flaw apparently by accident. When they realised what they had done, they attempted to undo the damage by deleting the code which had transferred ownership of the funds. Rather than returning the money, however, that simply locked all the funds in those multisignature wallets permanently, with no way to access them.

“This means that currently no funds can be moved out of the multi-sig wallets,” Parity says in a security advisory.

Effectively, a user accidentally stole hundreds of wallets simultaneously, and then set them on fire in a panic while trying to give them back.

“We are analysing the situation and will release an update with further details shortly,” Parity told users.

Hard fork
Some are pushing for a “hard fork” of Ethereum, which would undo the damage by effectively asking 51% of the currency’s users to agree to pretend that it had never happened in the first place. That would require a change to the code that controls ethereum, and then that change to be adopted by the majority of the user base. The risk is that some of the community refuses to accept the change, resulting in a split into two parallel groups.

Such an act isn’t unheard of: another hack, two years ago, of an Ethereum app called the DAO resulted in $150m being stolen. The hard fork was successful then, but the money stolen represented a much larger portion of the entire Ethereum market than the $300m lost to Parity.