CIA Fights To Hide
Its Invisible Ink
By James Langton
in New York
The CIA, the American intelligence agency, is fighting to preserve its secret recipe for invisible ink.
CIA lawyers say that classified First World War documents must not be made public because its spies still use the ink to send secret messages, using a German formula believed to have been passed to the United States in 1917 by British agents.
The files' existence was disclosed by a Washington pressure group campaigning against what it sees as excessive secrecy by government agencies. The formula is the oldest classified document still banned from public viewing at the National Archives, the US equivalent of the Public Record Office.
The James Madison Project, run by Mark Zaid, a lawyer, took legal action to have the records made public based on their age. Mr Zaid said he was astonished when the CIA objected.
"This is something they have managed to keep quiet for 80 years," he said. "But given the sophistication of foreign intelligence agencies and even terrorist groups today, it is difficult to imagine that a formula for secret ink could still be of any value."
Mr Zaid's scepticism was apparently shared initially by the judge who heard his freedom of information request in a Washington court last month and remarked that he remembered reading the formula on a cereal box as a child.
The CIA said that revealing the formula would compromise covert operations and make its messages "more vulnerable to detection . . . by hostile intelligence services or terrorist organisations". The judge eventually agreed, ordering the six files relating to the invisible ink kept secret until 2020.