William E. Colby faced an uneasy decision in late 1973 when he took over the Central Intelligence Agency: whether to make public the agency's internal accounting, then being compiled, of its domestic spying, assassination plots and other misdeeds since its founding nearly three decades earlier. Mr. Colby decided to keep the so-called family jewels a secret, and wrote in his memoir in 1978 that he believed the agency's already sullied reputation ... could not have withstood a public airing of all its dirty laundry. So why, at a time when the agency has again been besieged by criticism, this time for its program of secret detentions and interrogations since the Sept. 11 attacks, would the current director, Gen. Michael V. Hayden, decide to declassify the same documents that Mr. Colby chose to keep secret? General Hayden said it was essential for the C.I.A. ... to be as open as possible in order to build public trust and dispel myths surrounding its operations. The more that the agency can tell the public, he said, the less chance that misinformation among the public will fill the vacuum." It was this outlook that General Hayden, whose public relations skills are well known in Washington, brought to an earlier job. There, as director of the National Security Agency, he tried to overhaul the N.S.A.'s public image - that of the shadowy, menacing organization portrayed in the movie "Enemy of the State" - by inviting reporters to briefings and authorizing its officials to speak to the author James Bamford for his book on the agency, "Body of Secrets."