Sony was told by the Japanese government on Friday to strengthen its data security as the electronics and entertainment giant reels from a series of attacks by hackers.
The industry ministry officially instructed Sony to implement its own plan to improve management and protection of key information.
"This is a serious case, considering the nature of the information and the scope of the data leak," the ministry said in a statement.
In April the firm admitted personal information such as the user names, passwords, addresses and birth dates of more than 100 million people may have been compromised after hackers struck the PlayStation Network and Sony Online Entertainment services.
The hackers, staging one of the biggest data breaches since the advent of the Internet, may also have made off with credit and debit card data, the company said.
Sony said the data breach will likely result in at least a $170 million hit to operating profit this financial year in terms of insurance and damages costs.
The firm, which has since suffered attacks on more websites worldwide including in Greece and Thailand, announced the initial security breach on April 26, after discovering it on April 19.
"The fact that such a case happened and that it took time to report the incident to users as well as to this ministry is very regrettable," the ministry said.
The ministry said it had held three hearings about the case, and had reviewed the company's plans to improve its security.
The ministry also ordered Sony to tighten internal communications as well as exchanges with partner companies to further enhance protection of consumer information.
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