The White House's acting¹ cyber-security tsar has resigned from her post, according to the Wall Street Journal.

华尔街日报报道，白宫代理网络安全官员已辞职。

President Obama emphasised cybersecurity while campaigning

Melissa Hathaway told the paper she was standing² down for "personal reasons" and would return to the private sector³.

The former strategist was appointed as acting national cyber-adviser in February and was expected to be offered the post full time.

President Barack Obama has said that cyber-security is a high priority for his administration.

In May, the President announced plans for securing American computer networks against cyber attacks.

In recent years, US government and military bodies have reported attempts to infiltrate⁴（浸润，渗透） systems by hackers⁵.

He announced the creation of a cyber-security office in the White House, and said he would personally appoint a "cyber-tsar".

Ms Hathaway was widely regarded as the person to fill that post after taking on the role as acting senior director for cyberspace⁶ for the National Security and Homeland Security Councils in February.

She completed a review of cyber-security for the Obama administration in April.

At the time, Ms Hathaway said the job ahead was "a marathon（马拉松）, not a sprint⁷（短距离赛跑）."

Her successor has not yet been named by the White House.