Stephanie Powell has her sights set on the security industry. She graduated in May with a master's degree in organizational development and now hopes to leverage prior experience working for a small government contractor as she targets big consulting firms.

"There just seems to be more opportunity on the security side of the work that they do," says Ms. Powell, who is 31 years old and lives in Washington, D.C. "Right now, there's a lot of government spending in that area."

Ms. Powell is on to something. As the third anniversary of Sept. 11 passed over the weekend, security-related jobs continue to be among the fastest-growing in the country. The terrorist attacks helped awaken and transform an industry that continues to expand, creating a broad array of jobs to help protect everything from computer networks to people. At many companies, security-related positions have garnered more prestige as well as higher pay.

For people wishing to work for companies that bid on government homeland-security and military contracts, the most coveted credential is a security clearance. But other opportunities for a wide range of positions, from doctors to administrators, are available for people without clearances in security-related fields.

The government itself is leading the pack when it comes to hiring for security-related positions. "The federal government is increasing its hiring in all areas, but it's acute in homeland security," says Max Stier, president and chief executive of the Partnership for Public Service, a nonprofit group.

The Department of Homeland Security is home to more than 180,000 workers. Linguists and border-patrol agents are in great demand, according to Mr. Stier, and the intelligence agencies themselves expect to hire thousands of employees over the next several years. The Web site www.usajobs.opm.gov lists many current openings, and www.calltoserve.org provides guidance on how to get a government job.

The desire to hire senior-level security professionals in private as well as public organizations has risen significantly over the past few years. "Demand is greater than supply on a global basis," says Tim McNamara, managing director of the global-security and risk-management practice at Boyden Global Executive Search in Washington, D.C.

Mr. McNamara estimates that demand for senior-level security risk-management professionals has increased as much as 70% since the middle of 2002. The change also is reflected in pay. Corporate chief security officers typically earned $100,000 or less prior to Sept. 11, but many are now fetching between $250,000 and $500,000 a year in compensation, according to Mr. McNamara. His firm currently places between 30 and 40 senior-level security executives a year.

Today, you can even go back to school if you are interested in pursuing a security career. California University of Protection and Intelligence Management, which recently was issued state accreditation for many of its programs, offers degree and certificate programs that include counterterrorism planning, international intelligence analysis and "close quarter/combat tactics."

The school, based in San Jose, Calif., started enrolling students about five months ago. So far, it has received applications from about 300 people willing to submit to a thorough criminal background check, and it has enrolled about 70 students. People interested in the program have included chief security officers and intelligence agency staffers, while about 20% of applicants are trying to enter the security field with little or no prior experience.

"We see that there's a correlation between emerging job requirements and our curriculum," says Peter Rugato, the university's chief executive officer.

Meanwhile, the number of job openings for positions requiring a security clearance has also risen. ClearanceJobs.com, a job board that posts only such positions, listed 553 jobs last week, a 150% increase over the same time last year, according to Evan Lesser, co-founder of the site. Since January, 1,300 candidates with security clearances have registered on the site each month, up nearly 110% from the rate in 2003.

There are an estimated two to three million people in the U.S. who currently have active security clearances, and between 350,000 and 450,000 candidates are awaiting clearances, according to Mr. Lesser. Sensitive information is typically classified in three categories -- confidential, secret and top secret -- and getting a clearance requires an extensive background investigation.

People are granted security clearances only if their job requires it. You can be sponsored by a company, which will initiate the process with the government. Or you can join the military or reserves, since many active service members have clearances.

Having a security clearance can go a long way toward getting noticed by certain employers. At job fairs run by companies such as SecurityClearanceExpo.com, only job seekers with an active clearance can attend.

But government contractors are frequently open to hiring graduating college students without clearances, says Jeff Foster, vice president of operations for SecurityClearanceExpo.com. "If they really find someone that's the diamond in the rough, they're going to try to process the person very quickly," he says.