The National Security Agency announced yesterday that it has declassified a report that is over two hundred years old.
The newly declassified report, entitled “Cryptology: Instruction Book on the Art of Secret Writing,” dates from 1809. It is part of a collection of 50,000 pages of historic records that have just been declassified by NSA and transferred to the National Archives.
The bulk of the newly released documents are from World War II and the early post-War era. (NSA itself was established in 1952.) A list of titles released to the National Archives is here (pdf).
Last April, the Central Intelligence Agency declassified several documents on the use of “invisible ink” that dated from the World War I era. But those were not even a century old.
You can't make this stuff up.