Big bitcoin exchange 'fixes' trading glitch

Zynga on smartphone Game maker Zynga's decision to accept bitcoins pushed the value of the virtual cash to new heights

Related Stories

Trading on one of the largest bitcoin exchanges is set to resume after it identified a technical problem that left it vulnerable to disruption.

MTGox halted transfers of the digital currency to external addresses on 7 February after it spotted what it called "unusual activity".

The company's action caused bitcoin values to slump from their mid-January high of $1,000 (£600) to about $540.

MTGox said customers should be able to start withdrawing funds "soon".

The Tokyo-based firm said its investigation into the unusual activity revealed a loophole that thieves could use to fool the transaction process into sending double the correct number of bitcoins.

It also left it vulnerable to attacks, which slowed down the rate at which coins could be bought and sold.

Staff confronted

This problem revolved around what are known as bitcoin wallets - an essential part of the entire bitcoin system and the place where bitcoin addresses - the virtual post-boxes where each bitcoin is stored - are kept.

Cash withdrawals and transfers of bitcoins to - rather than from - bitcoin wallets were unaffected by the loophole.

The suspension of withdrawals led some bitcoin traders to travel to Japan to confront MTGox's staff and demand the return of their currency.

The loophole was also thought to have been exploited by thieves, who stole about $2.7m in bitcoins from the Silk Road 2 website.

In a statement, MTGox said it had found a way to combat the loophole by issuing unique identifiers for each transaction. This, it said, should prevent "fraudulent" abuse of the transaction process.

So far, MTGox has not said when withdrawals might start again but said it would issue another update by 20 February at the latest.

When withdrawals do re-start, MTGox said it would moderate the pace of trades to iron out any problems with the new system.

More on This Story

Related Stories

The BBC is not responsible for the content of external Internet sites

More Technology stories


Features & Analysis

  • Cartoon of women chatting on the metroChat wagon

    The interesting things you hear in a women-only carriage

  • Replica of a cargo boxSpecial delivery

    The man who posted himself to the other side of the world

  • Music scoreFinal score Watch

    Goodbye to NYC's last classical sheet music shop

  • Former Secretary of State Hillary Rodham Clinton checks her Blackberry from a desk inside a C-17 military plane upon her departure from Malta, in the Mediterranean Sea, bound for Tripoli, Libya'Emailgate'

    Hillary gets a taste of scrutiny that lies ahead

BBC Future


The future of CGI... from 1982

How we forecast computer animation back then


  • A cyborg cockroachClick Watch

    The cyborg cockroach - why has a computer been attached to this insect’s nervous system?

Try our new site and tell us what you think. Learn more
Take me there

Copyright © 2015 BBC. The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.