Bitcoin exchange Mt. Gox plans to lift its suspension of external Bitcoin transfers soon after fixing a weakness in its accounting process that left it susceptible to denial-of-service attacks, company representatives said Monday.

As Ars reported last week , the Tokyo-based Mt. Gox was one of at least two Bitcoin exchanges that temporarily suspended withdrawals after coming under attacks that deliberately flooded it with malformed transaction records. The phantom transactions didn't allow attackers to steal money or permanently tamper with the central accounting system for the digital currency, but it had a noticeable effect on some exchanges. The malformed records created discrepancies in the effected exchange's accounting systems that caused them to fall out of sync with the network. The exchanges then experienced slow downs as they recalculated their account balances. The attack and the vulnerability it exploited came to public attention through the research of Bitcoin wallet developer Blockchain.info.

In a statement issued Monday, Mt. Gox representatives said:

We apologize for the inconvenience caused by the recent suspension of external Bitcoin transfers. Fortunately, as we announced on Saturday, we have now implemented a solution that should enable withdrawals and mitigate any issues caused by transaction malleability (please see our previous statements for details on this issue). Thanks to our friends at Blockchain.info, Mt. Gox now has a workaround that will use a unique identifier created by Blockchain to show whether transactions have been modified or not. This will prevent any fraudulent use of the malleability issue and protect the assets of our customers. Resuming Withdrawals With this new system in place, Mt. Gox should be able to resume withdrawals soon. At the beginning we will do so at a moderated pace and with new daily/monthly limits in place to prevent any problems with the new system and to take into account current market conditions. In order to launch the new system, we are going through the following steps: Re-indexing the entire Blockchain (approx. 32 million entries)

Fully deploying the new NTX ID

Implementing a new Bitcoin withdrawal queue that needs to be tested We will update everyone again by Thursday at the latest.

Mt. Gox is also adding a new login system that automatically sends users an e-mail each time their account is accessed. The company continues to recommend customers make use of two-factor authentication.