The Homeland Security Department official in charge of protecting the nation's physical and computer infrastructure is stepping down at the end of the month in the latest in a string of departures at the department's struggling cyber-security division.
The announcement by Robert P. Liscouski, the department's assistant secretary for infrastructure protection, comes as technology executives and experts increasingly say that the Bush administration is giving short shrift to computer security.
Robert Liscouski is stepping down to join a Reston firm.
Attacks continue to proliferate and have become more sophisticated, whether they be viruses and phony solicitations aimed at home computer users or assaults on the networks of companies and other organizations.
This week, for example, George Mason University said hackers gained access to a database of names and Social Security numbers of the school's 32,000 students and employees.
Liscouski has been criticized inside and outside the department for impeding cyber-division initiatives that might give it a higher profile. Liscouski, who said he is resigning to become chief executive of Content Analyst Co. LLC, a Reston company that gleans intelligence from analyzing text, defended his record.
"I believe DHS has made tremendous first steps," he said.
Amit Yoran, who headed the agency's cyber-security division, resigned in October. Yoran did not criticize Liscouski publicly, but sources close to him said he was frustrated at his inability to make the agency more aggressive against cyber-security threats. The sources spoke on the condition of anonymity because they do not want to jeopardize relations with the department.
Yoran was the third person to quit the post in 18 months. Also leaving the department this month is Lawrence C. Hale, the cyber-security division's deputy director.
In July, the Homeland Security Department's inspector general found that the division's efforts suffered from a lack of coordination, poor communication and a failure to set priorities.
The division "must address these issues to reduce the risk that the critical infrastructure may fail due to cyber attacks," the report said. "The resulting widespread disruption of essential services after a cyber attack could delay the notification of emergency services, damage our economy and put public safety at risk."