The National Security Agency has declassified the finding aid for a collection of thousands of historically valuable NSA scientific and technical records that were transferred to the National Archives (NARA) last year.

Up to now the contents of the collection had been opaque to the public. As David Langbart of NARA described the collection to the State Department Historical Advisory Committee last year:

“These records mostly consist of technical, analytical, historical, operational, and translation reports and related materials. Most of the records date from the period from the 1940s to the 1960s, but there are also documents from the 1920s and 1930s and even earlier. The NSA reviewed the records for declassification before accessioning and most documents and folder titles remain classified. [. . .] The finding aid prepared by NSA was the only practical way to locate documents of interest for researchers, but it is 557 pages long and is classified.”

When confronted with this impasse last month, the National Security Agency to its credit moved to rectify matters by declassifying the finding aid, which is now available as a .pdf file here (or as an .xlsx file here).

Most of the folder titles (listed beginning on p. 13 of the .pdf file) deal with narrow, highly specialized aspects of cryptologic history prior to 1965. A few examples picked at random: German Signals Intelligence in World War II; A Compilation of Soviet VHF, UHF and SHG Activity by Area, Source and Service; Hungarian Army Communications; Description of Chinese Communist Communications Network; and so on. Those folders all remain classified. But armed with the titles and file locations of such records (and of thousands more), researchers can now pursue their declassification.

Release of the finding aid by NSA “should help interested researchers gain access to relevant material more readily,” said David J. Sherman of NSA, who facilitated disclosure of the document.