WWI Secret Writing Techniques

[Rev.Cambeul]

Recently released from the CIA archives.

https://www.cia.gov/library/readingroom/print/4187

CIA Declassifies Oldest Documents in U.S. Government Collection

The Central Intelligence Agency today declassified the United States Government's six oldest classified documents, dating from 1917 and 1918. These documents, which describe secret writing techniques and are housed at the National Archives, are believed to be the only remaining classified documents from the World War I era. Documents describing secret writing fall under the CIA's purview to declassify.

"These documents remained classified for nearly a century until recent advancements in technology made it possible to release them," CIA Director Leon E. Panetta said. "When historical information is no longer sensitive, we take seriously our responsibility to share it with the American people."

One document outlines the chemicals and techniques necessary for developing certain types of secret writing ink and a method for opening sealed letters without detection. Another memorandum dated June 14, 1918 - written in French - reveals the formula used for German secret ink.

https://www.cia.gov/library/readingroom/docs/Secret-writing-document-one.pdf
https://www.cia.gov/library/readingroom/docs/Secret-writing-document-two.pdf
https://www.cia.gov/library/readingroom/docs/Secret-writing-document-three.pdf
https://www.cia.gov/library/readingroom/docs/Secret-writing-document-four.pdf
https://www.cia.gov/library/readingroom/docs/Secret-writing-document-five.pdf
https://www.cia.gov/library/readingroom/docs/Secret-writing-document-six.pdf

<a href="https://www.cia.gov/library/readingroom/docs/Secret-writing-document-two.pdf" target="_blank">https://www.cia.gov/library/readingroom/docs/Secret-writing-document-two.pdf</a>