A cryptology instruction book... 202 years old. A photograph of the U.S. Army's cypher bureau... from 1919. A breakdown of Russian electoral districts... circa 1948. Schematics for a magnetic tape memory system... nearly half a century old.

These are just some of the items that, had you seen them, would have irreparably damaged U.S. national security. These are just a few of the documents, mere citizen, that for decades were far too sensitive for your uninitiated eyes.

At least, that's what the American intelligence community would have you believe. Earlier this week, the National Security Agency announced that it had declassified and released to the National Archives "over 50,000 pages of historic records," according to an agency statement. The document dump was "the first in a series of releases planned over the next two years" as part of NSA's "commitment" to comply with President Obama's January, 2009 memo demanding more transparency from federal agencies. Last month, the CIA released a trove of allegedly-explosive information from World War I, including the 90 year-old German formula for invisible ink.

Included in this new motherlode (.pdf) of supposedly secret-packed documents: a 1944 report on Japanese merchant ships, a 1946 dossier on Chinese railroads, and a 1954 German article on Lenin's use of secret writing (with milk) while in prison. Presumably, this refers to Lenin's stint in Siberia, in the mid-1890s. Exactly why Vladimir Ilyich's reliance on lactose letters needed to be kept under wraps for 11 decades, the NSA doesn't say.

The timing of the document dump is delicious, however. The government's five-year effort to charge an NSA employee with violating the Espionage Act collapsed yesterday. Thomas Drake was charged with leaking to a reporter damaging – though not necessarily secret – information about a near-useless $1.2 billion project. Presumably, the government would have rather kept its billion-dollar boondoggle to itself for another two hundred years.

Photo: courtesy of Mil-Spec Monkey

See Also:- Revealed: Skin Messages, Invisible Ink and More Secret WWI Spycraft