Even as Sony moves to relaunch its PlayStation Network service across the world, one country that is not on board is Japan. 

A Japanese government official who spoke to Dow Jones Newswires yesterday, cited security concerns for the country not allowing Sony to launch PlayStation Network within its borders.

"As of May 13, Sony was incomplete in exercising measures that they said they will do on the 1 May press conference," Kazushige Nobutani, Japan's director of media and content in the country's Ministry of Economy, Trade, and Industry told Dow Jones. 

According to industry sources, the Japanese appear to be a little more strict with Sony than countries in other regions that have already allowed the company to reboot its network including the US, Europe, Australia, New Zealand and the Middle East.

PlayStation Network troubles first hit the company when its  servers were attacked by a hacker or hackers, following which its was forced to take down its PlayStation Network, Qriocity, and Sony Online Entertainment services.

It said  that over 100 million customers had their personal data stolen. Sony has spent the last several weeks working on improving the security of its services to limit the chances a recurrence of the problems.

Sony, started the relaunch of its PlayStation Network service on Saturday. According to the company, it would be made available first to customers in the Americas, Europe, Australia, New Zealand, and the Middle East. 

"The company has made considerable enhancements to the data security, including updating and adding advanced security technologies; additional software monitoring and penetration and vulnerability testing; and increased levels of encryption and additional firewalls," Sony said in a statement accompanying the relaunch of its service. "The company also added a variety of other measures to the network infrastructure, including an early-warning system for unusual activity patterns that could signal an attempt to compromise the network."

However, Japanese officials do not seem to be fully convinced about Sony's claims. In the interview with Dow Jones, Nobutani said Japan wanted to know that Sony was taking adequate measures to prevent another breach.

"There were similar cases in the past that were caused by other firms," Nobutani said in the interview, "and we are asking Sony whether their measures are good enough when compared to countermeasures taken in the past."

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