Coincheck Inc. users withdrew ¥40.1 billion ($373 million) from the cryptocurrency exchange on Tuesday, the first day customers were allowed to pull out in the wake of the cybertheft of ¥58 billion ($533 million) worth of digital currency last month.

The target of the biggest theft of digital coins in history on Tuesday began allowing yen withdrawals for the first time, triggering the exodus of money. Chief Operating Officer Yusuke Otsuka is sticking to a promise to compensate users, though he wouldn't go into the root causes of the heist during a hastily arranged briefing in Tokyo.

The exchange is considering capital alliances and has engaged an external firm to verify its security before resuming full operations, he told reporters. Coincheck earlier submitted a report to the Financial Services Agency explaining how the hack occurred, what kind of support will be provided to customers and how systems will be bolstered to prevent future hacks, the company said in a separate statement.