Joel McNamara first told me about NONSTOP and its commonly
associated classified codeword, HIJACK, both somehow related
to Tempest.
When you do a search on either of them you get hundreds
(or 1000s) of hits for the generic terms "non-stop" and "hi-jack"
but few entries for the codewords, and then as standards in
military security documents.
It's as if the codewords were picked to be camouflaged by the
generics. And, because codewords are usually set to have
no relation to the protected material, they probably are not
descriptive -- but could be, just to outfox the smarties.
The NONSTOP doc released to us was first issued in 1975
and has gone through 4 reprintings, the latest in 1987. And
it continues to be cited as still in effect, though usually such
standards are updated at least every 5 years. So there may
be a later one which would account for its partial release
after first denial.
It's intriguing to read Spycatcher (1987) while reading the
Tempest docs. I had not read Wright's most informative
book, and regret not having done so. (The Story of Hut 6,
too, by Gordon Welchman -- luckily found both in a
military used-bookstore.)
For those who have not read Spycatcher, Peter Wright
was MI5's first scientist, and entered the service after
WW2. He specialized in the technology of counterintelligence
and with a few others cooked up a host of ingenious means
to spy on spies and suspects. A specialty was the
extraordinary use of electromagnetic science -- radio,
telephone, acoustic, resonance, and more -- applying
scientific abilities well in advance of technicians and
engineers. Some of his ideas were so advanced his
bosses said impossible, until he proved effectiveness.
Then Wright quickly became the savior of officers
who could not understand why Britain's enemies kept
outsmarting them -- usually with advanced technological
means. Wright changed that, but often got at odds with
non-scientific personnel whose faith was HUMINT.
Among others, he worked closely with GCHQ on occasion
to provide technical attacks on cryptosystems which could
not be broken by cryptanalysis. Thus his research on the
cryptosecrets revealed by compromising emanations from
devices, cabling, furniture, construction materials, and a host
of ordinary physical objects in and near cipher rooms -- all
of which emitted signals that could be acquired and interpreted
by careful tuning for comprehension. He writes of amazing
methods of acquiring signals, and it is no wonder HMG
fought to prevent publication of Spycatcher.
What he did not write about must be even more wondrous,
and it makes you think he could pick up your brain waves
if you were part of particular triangulated antenna.
Maybe NONSTOP and HIJACK have nothing to do with
the stuff Wright excelled at. Still, reading Spycatcher
along with the Tempest docs -- and now Stephen
Budiansky's "Battle of Wits: The Complete Story of
Codebreaking in World War II," (2000) -- certainly
demonstrates how much of codebreaking has been
done by covert technical and physical means, even
as we are told misleading cover stories.
Are these latest crypto-revelations disinformation?
Historically nearly all have been. Ha. Ha. Ha.