Online gaming and access to unexpired movie rentals will be the first services to return on the PlayStation Network, while Qriocity users will be able to use the Music on Demand service. Other functions, including the PlayStation Store, will be available by mid-May, said Kaz Hirai, head of Sony’s gaming division, during a rare Sunday news conference.
[Read: Is Sony’s PSN Welcome Back Enough–Did You Already Buy an xBox 360?]
“We’d like to extend our apologies to the many PlayStation Network and Qriocity users who we worried,” said Hirai. “We potentially compromised their customer data. We offer our sincerest apologies.”
Rebuilding After Attack
Sony took the two services offline on April 20 after an intrusion was detected on the network’s servers, which live in an AT&T data center in San Diego. Sony discovered the intrusion after it was alerted to unusual network activity a day earlier, said Hirai. (See also PlayStation Network Hack Timeline.”)
Sony initially responded by asking a computer security company to investigate the intrusion. When it became apparent that customer information could have been stolen, Sony employed a second specialist company, said Hirai.
Sony’s investigation is still continuing and, as such, the company still doesn’t have a clear picture of what exactly was stolen and how many accounts were affected. The company believes there is a high probability that personal information was taken, including usernames for the service and associated passwords in encrypted form, names, addresses, birthdates and e-mail addresses. Sony hasn’t determined how many accounts were hit, but the attack could potentially affect all 77 million accounts.
User Data Status Uncertain
About 10 million accounts have credit card numbers associated with them, but Sony said it had no evidence those numbers were stolen. The credit card numbers, unlike the personal information, are stored in an encrypted database, although Sony has not said what encryption system was used.
Nevertheless, Sony advised customers to watch out for unusual activity on their credit card accounts. It has discovered no such cases so far, said Hirai. Sony will pay the cost of reissuing credit cards based on user requests.
The attack was launched from an application server that sits behind a web server and two firewalls on Sony’s network, said Shinji Hasejima, Sony’s chief information officer.
“It was a very sophisticated technique that was used to access our system,” said Hasejima.
Video: Sony’s Executive Apology for PSN Attack
The initial attack was disguised as a purchase, so wasn’t flagged by network security systems. It exploited a known vulnerability in the application server to plant software that was used to access the database server that sat behind the third firewall, said Hasejima.
Management at Sony Network Entertainment International, the company that manages the network platform for the two services, wasn’t aware of the vulnerability, said Hasejima.
Beefing Up Security
The appointment of a chief information security officer will be one of the measures taken by Sony to ensure such a mistake doesn’t happen 
When services return, Sony will ask all users to change their account passwords.
The company is also planning to offer selected software downloads at no charge and an one month extension for users on the subscription-based PlayStation Plus service.
Martyn Williams covers Japan and general technology breaking news for The IDG News Service. Follow Martyn on Twitter at @martyn_williams. Martyn’s e-mail address is martyn_williams@idg.com