Sony chief executive Kazuo Hirai said that both former and current employees at its movie studio were victims of "one of the most vicious and malicious cyber attacks that we have known", in his first public comments on November's hack.
Opening a press conference at the International Consumer Electronics Show in Las Vegas, Mr Hirai said he was "very proud" of employees and partners of Sony Pictures who had stood up against the hackers' "extortionist efforts" and worked "literally 24 hours a day, sometimes for days on end", to release The Interview online after North American cinema chains boycotted the film in the face of threats of violence.
"I have to say that freedom of speech, freedom of expression, freedom of association, these are very important lifebloods, lifelines of Sony and our entertainment business," he said.
The Federal Bureau of Investigation said that it had found evidence linking the North Koreans to the cyber attack, after The Interview parodied the country's leader Kim Jong Un. North Korea has denied the charge, describing fresh US sanctions imposed on its agencies and officials linked to its arm trading and intelligence establishment as hostile and repressive.
Mr Hirai said that Sony would continue to invest in its content business, which has been a central plank of his turnround strategy.
Having spun off its television business and sold its personal computer brand, the Japanese consumer electronics and entertainment group still expects an annual loss of $2 billion as it restructures its struggling mobile unit.
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Despite the large streamlining costs and the cyber attacks, Sony shares rose 35 per cent last year. Investors are pinning hopes on Mr Hirai's turnaround strategy and his reshuffled management team including a new chief financial officer and a new head for its mobile division.
"I have been committed to putting Sony on a course for future growth in fiscal 2015 and beyond. Our efforts have been concentrated in areas where we are uniquely positioned to outperform the competition," he said.
Vital to that plan is the PlayStation gaming business, which sold 4.1 million of its latest PS4 consoles over the holiday season. That takes total sales to 18.5 million since it launched in November 2013 and shows Sony is maintaining its lead in gaming over Microsoft and Nintendo despite adverse publicity around the hacking.
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"This is exceeding the rate of adoption of any other PlayStation platform," Mr Hirai said.
As sales of traditional consumer gadgets fall, one other growth pillar for Sony has been its image sensors used in cameras and smartphones including Apple's iPhones. Mr Hirai said the company will aim to tap into increasing demand for sensors used in cars, saying the market is expected to expand four-fold in the next five years.
Sony's CES announcements included new smart-home concepts, such as a speaker embedded in a lamp, and a new steel version of its smart watch. It also announced that its latest television sets would run Google's Android software, in contrast to Samsung, which is using its own Tizen platform for internet-enabled TV.