Interested firms are then required to register with the agency and submit a 500-word essay detailing their offerings and capabilities. When the NSA wants to hire a firm for a specific project or buy a particular technology, requests for proposals are sent to registered companies.

NSA's contract awards are not always announced, but Gatanas said the agency does hold competitions for most of its acquisitions.

The biggest challenge for most companies attempting to strike a deal with the NSA is its stringent security clearance procedures. The agency has its own clearance process that includes polygraph tests. The process takes an average of more than 200 days to complete, although the agency is trying to reduce that time to four months or less.

In addition, companies generally must already have contracts in place to get clearances, although Gatanas's office has begun to sponsor some firms through the process before they've been awarded contracts to get more new companies involved.

Pragmatics Inc., of McLean, a 19-year-old company that provides software engineering and information security services, won its first contract with the agency two years ago after attending an information session for small businesses. That contract -- which included orders for a variety of technology products and services -- was the company's first major deal with an intelligence agency, said Rick Roach, director of information assurance at the 200-person company.

ManTech International Corp., which in April won a four-year, $22.5 million deal to do engineering and maintenance work on NSA communication systems, has been doing business with the agency since the early 1980s. Peter B. LaMontagne, ManTech's senior corporate vice president, said doing business with the NSA is not that different from doing business with any other defense agency.

The biggest challenge, he said, was finding employees with the right skills who either have a clearance already or are willing to go through the agency's clearance process. "When it comes to dealing with NSA, companies just have to realize that security is the most important issue," LaMontagne said.

Ellen McCarthy writes about the local tech scene every other Thursday. Her e-mail address is mccarthye@washpost.com.