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Last month the National Security Agency announced the declassification of various historic records as evidence of its “commitment to meeting the requirements” of President Obama’s policy on openness and transparency. Among the newly declassified records was a 200 year old publication on cryptology. (“NSA Declassifies 200 Year Old Report,” Secrecy News, June 9, 2011.)

NSA listed the 1809 study as a “highlight” of the new releases in a press statement, and the National Archives featured it in a promotional blog posting. But upon inspection, it turns out that the newly released document was already in the public domain and freely available online.

Instead of providing cause for celebration or congratulation, the NSA “release” is a disturbing sign of futility and irrelevance in the nation’s declassification program.

The June 8 NSA press statement hailed the disclosure of “early publications on cryptography, including ‘Cryptology: Instruction Book on the Art of Secret Writing’ from 1809. In fact, the document is a German work and its real title is “Kryptographik: Lehrbuch der Geheimschreibekunst…” by Johann Ludwig Klüber (1762-1837), who was the first Professor of Law at the University of Heidelberg.

According to a June 14 blog post by James Rush of the National Archives, this work was among the German government records that were seized by U.S. forces after the defeat of Germany in World War II, and it found its way into U.S. intelligence files.

Though the NSA press statement seemed to indicate that the full publication was being disclosed, the material that was released by NSA was actually just a 40 page abstract and excerpt of the author’s much longer work. A copy of what was transferred to the National Archives is now posted here (pdf).

The cover sheet indicates that the document was classified as Secret, and that it was formally declassified on November 12, 2010 by D. Janosek, NSA Deputy Associate Director for Policy and Records, along with a second reviewer who was identified only by his or her initials.

But what neither the National Security Agency nor the National Archives seemed to realize is that not only had the source material never been classified — and so could not properly be “declassified” — but that it was already publicly available. The full 532 page text of the 1809 study — not just a 40 page abstract — was actually digitized several years ago and published online through Google Books.

Two obvious inferences may be drawn from this episode. First, there is extravagant overclassification at the National Security Agency, as in many other corners of government. This means that access restrictions are being imposed on records that do not require or deserve such protection. Second, there is a lack of effective oversight mechanisms to promptly identify and correct such instances of overclassification. There are always going to be classification errors, so there need to be robust error correction mechanisms. Ideally, Google Books would not be one of them.