Sony has blamed forensic analysis for delays in notifying more than 100 million PlayStation Network and Online Entertainment service users that their personal data may have been stolen in hacker attacks.
The company has faced a barrage of criticism for taking almost a week after detecting an intrusion which led to suspension of the PSN to notify users of the data breach.
"I wish we could have got the answers we needed sooner, but forensic analysis is a complex, time-consuming process," said Sony US chief Howard Stringer in a letter to customers.
"Hackers do their best to cover their tracks, and it took some time for our experts to find those tracks and begin to identify what personal information had or had not been taken," he said.
Sony is desperate to win back the confidence and goodwill of its customers after one of the biggest-ever breaches of personal information.
Stinger emphasises in the letter that, to date, there is no confirmed evidence that any credit card or personal information has been misused.
He also says Sony is moving ahead with plans to help protect customers from identity theft around the world and will be offering a "Welcome Back" package once its networks are restored.
The company has already launched a programme for US PlayStation Network customers that includes a $1m identity theft insurance policy per user. Announcements for other regions will be coming soon, the company says.
The Welcome Back package will include a month of free PlayStation Plus membership for all PSN customers, as well as an extension of subscriptions for PlayStation Plus and Music Unlimited customers to make up for time lost, says Stringer.
Sony has not made any firm commitment on when its online gaming services will be up and running again, but Stringer hints that it may be soon, saying the service will be restored "in the coming days".