[DigitalToday reporter Choi Jae-won (최재원)] Some services on Japanese company Sega's arcade game network have been restored a week after it was shut down due to unauthorised external access. Eight Bandai Namco group games, including Taiko no Tatsujin, resumed test operations, but Sega's own games have not returned to normal.

On Nov. 9, local time, Japanese media outlet ITmedia reported that Bandai Namco Experience has been sequentially starting test operations since Nov. 8 for eight of its arcade games that use the ALL.Net communications system.

The games include Taiko no Tatsujin, Mobile Suit Gundam Extreme Vs. 2 Infinite Boost, Mario Kart Arcade Grand Prix Deluxe, The Idolmaster TOURS and Wangan Midnight Maximum Tune 6RR PLUS.

JoJo's Bizarre Adventure: Last Survivor, Fishing Spirits Wonder and Mobile Suit Gundam Arsenal Base are also included in the restart.

Online matches and use of game cards are available even during the test operations. Bandai Namco instructed each game centre operator to power on the machines, check whether they are operating normally and then resume operations. Scheduled updates and limited-time events will have their timetables adjusted in line with the recovery status.

The incident began on servers related to ALL.Net, which is operated by Sega Fave under Sega Sammy Holdings, and the Aime user authentication service.

Sega Fave confirmed unauthorised access by an outside party and shut down related services from 3 p.m. on Nov. 1. Disruptions occurred not only to online games but also to the use of Aime cards, game centre location searches and some online services.

Damage spread to Bandai Namco games that share the servers, disrupting normal business operations at multiple game centres.

Some functions for Bandai Namco products have been restored, but Sega games remain under inspection. As of 9 a.m. on Nov. 8, no date had been set for resuming Sega's own services, and the next update was scheduled for 9 a.m. on Nov. 10.

Whether any information was leaked is also under investigation. Sega Fave said an initial probe found no confirmed leak of information from customers and business partners, and that payment information such as credit cards was not affected.

The incident underscored the importance of security management because a breach of the shared network needed to operate games can halt services from multiple developers at the same time.