National Security Agency

She remembers it was 2 p.m. on Sept. 3 when a taxi delivered the yellow telegram to her door in New Jersey. Teresa Durkin RTC expected it to be from her brother in the military, needing a ride to another air base. Instead, it was from the Air Force, and it started with five awful words: "It is with deep regret "That was 39 years ago, and yesterday the federal government finally recognized the sacrifice of her late brother -- Master Sgt. George P. Petrochilos -- and dozens of other airmen who died in some of the most secret service of the Cold War.The National Security Agency unveiled the National Vigilance Park and Aerial Reconnaissance Memorial at its headquarters near Fort Meade.

The National Security Agency has spent the past eight years inching out of the shadows, courting public opinion and opening its doors in limited ways to win back wavering congressional support. But since Sept. 11, the agency has reverted to a place of secrets and seclusion, as shut down to outsiders as it was at the height of the Cold War. Its focus has narrowed to one mission: finding Osama bin Laden and his terrorist followers. The agency has called back more than 100 NSA veterans, most of them retired to nearby Howard and Anne Arundel counties.

PALO ALTO, Calif. -- If you've ever ordered a book over the Internet or checked the balance in your bank account, a flash across your computer screen probably said your transaction was "secure" -- a promise that your financial information would not be broadcast across the Internet.Standing behind such a promise is Whitfield Diffie, who looks as if he took a wrong turn at Woodstock and emerged in the blue-suit world of Washington.This math whiz-turned-inventor-turned-lobbyist has become a fixture of Senate subcommittee rooms, American Bar Association meetings, math conventions and even military conferences.

When the National Security Agency trains its agents in the highly technical art of eavesdropping, they naturally need to practice.And the law gives them the right to practice on you.NSA agents can hone their listening skills and test their equipment on the most intimate telephone calls of ordinary U.S. citizens, as long as notes and tapes are destroyed "as soon as reasonably possible.""We listened to all the calls in and out of Washington," says one former NSA linguist, recalling a class at the Warrenton Training Center, a CIA communications school on a Virginia hilltop.

Zug, Switzerland -- For four decades, the Swiss flag that flies in front of Crypto AG has lured customers from around the world to this company in the lake district south of Zurich.Countries shopping for equipment to encode their most sensitive diplomatic and military communications value Switzerland's reputation for business secrecy and political neutrality. Some 120 nations have bought their encryption machines here.But behind that flag, America's National Security Agency hid what may be the intelligence sting of the century.

While Texans don't apologize for having oil reserves and Floridians aren't bashful about their warm weather and sunshine, Marylanders are seldom caught boasting about one of the state's most impressive resources -- a veritable army of people who know how to spy in cyber space. The presence of the National Security Agency in Fort Meade has long been the least-talked-about jobs engine in the state's economy for obvious reasons. It's a government agency so secretive that neither its budget nor the size of its payroll is ever officially revealed.

George W. Nitsch, a former Baltimore police sergeant and guard for the National Security Agency, died of heart failure Wednesday at Chester River Hospital Center in Chestertown. He was 87. Mr. Nitsch - known as Bill to family and friends - was born and raised in Southwest Baltimore. His early world was the neighborhood around his Ashton Street home. He went to grammar school at St. Benedict Church, and he ended up marrying a schoolmate, Rita M. Heaney, whom he met through her brother, who was his best friend.

Espionage watchers consider the early 1990s a low point for the National Security Agency.Around that time, the Internet was beginning to change how people communicate, becoming a new tool for everyday life. But while the rest of the nation was e-mailing each other, NSA was still delivering top-secret intelligence reports to Washington inside pizza boxes.An agency that in its heyday had helped create the first computers had become appallingly low-tech. Gen. H. Norman Schwarzkopf even complained about it during 1991's Persian Gulf war when he said intelligence reports on Iraq's military were taking too long to reach his hands.

An editorial in today's Perspective section misstates the timetable for a study of U.S. intelligence agencies by a commission headed by former Defense Secretary Harold Brown. The panel is to conclude its review in the spring.The Sun regrets the error.THE NATIONAL SECURITY Agency, the code-breaking and electronic spying organization headquartered at Fort Meade, has many nicknames. Some claim the initials NSA stand for "No Such Agency" -- because it was long so secret even its existence was officially denied.