NSA's History of Communications Security — For Your Eyes, Too

Phil Sp. writes "Government Attic, those fine investigative pack rats, have outdone themselves this time. Just posted: a declassified NSA document entitled A History of Communications Security, Volumes I and II: The David G. Boak Lectures [PDF] from 1973 and 1981. This is an absolutely fascinating look into how the NSA viewed (views?) communications security and touches on all sorts of topics, including public key crypto, economics, DES, tamper-resistance, etc. It was seemingly from a collection of lectures to new employees. The first 85 pages are heavily redacted but the remaining 80 or so are largely intact. It even concludes with a cryptogram puzzle for the reader!"

Comments

What I heard a while back

[Anonymous Coward]

The NSA uses ---------- to monitor ------------- by ----------- and ------------ through a network of ------------. It was really pretty interesting.

The solution:

[Tubal-Cain]

It even concludes with a cryptogram puzzle for the reader

The answer?
FRANK SHOEMAKER WOULD CALL THIS NOISE.

Re:The solution:

[Darth_brooks]

Wrong answer, Hans. Care to try for double jeopardy?

It reads: ALWAYS DRINK YOUR OVALTINE

Duh.

Their "FLOP" section was blanked out. :(

[gurps_npc]

I was so hoping that they turned honest and revealed some errors. Never trust someone that refuses to admit they were wrong. If you can't recognize when you are wrong, you don't know when you are right.

Dan Brown

[Arancaytar]

It even concludes with a cryptogram puzzle for the reader!"

Are you sure you didn't pick up Digital Fortress by mistake? :P

Why was it classified

[Techmeology]

Why was it classified? Given that all good security must be based on rigorous unbreakability, not secrecy, the analytical powers of many eyes would have been useful. Also, I'm opposed to governmental secrecy.

Re:Why was it classified

[FishWithAHammer]

Security through obscurity isn't security, but security plus obscurity is better security so long as the obscurity holds.

Re:Why was it classified

[QuantumRiff]

You are correct, however, sometimes you don't want to know about bad algorithms.. or more accurately, you don't want your enemies to know that you've cracked their codes.

Sometimes, things are just politically sensitive.. ie, We cracked the code, realized that country X placed a spy into country Y, we notified country Y, and the spy for country X had a tragic accident...

Re:Why was it classified

[DerekLyons]

Given that all good security must be based on rigorous unbreakability, not secrecy

That's commonly held belief of security amateurs. In reality, obscurity is a valuable tool in the arsenal of the security professional - because an attacker cannot be prepared to address a measure that he does know the existence of beforehand. For example - a visible set of VCR's in a place equipped with visible cameras... but they are dummies with the real ones (or a backup set) behind a nondescript door.
 
 

the analytical powers of many eyes would have been useful

The analytical power of many experienced and knowledgeable eyes - sure. But those eyes have clearances and access to the document. Just because the general public doesn't see it, doesn't mean that a lot of qualified people haven't.

Re:Why was it classified

[darkmeridian]

In the real world, knowing what people know is very important. Releasing what you know and what you know others to know would be a disastrous turn for a national security agency (NSA). Whether the bad guys fell for your double agent's lies, for instance, is a crucial fact. If the NSA has compromised a whole bunch of communications systems, we don't want the people using the systems to know that they're compromised!

I found some of the redacted text

[Tracy Reed]

So here I am reading the document linked in this story when I get to page 85 about tempest. I encounter the phrases "He sauntered past a kind of carport jutting out..." and "a carefully concealed dipole antenna, horizontally polarized." And I thought...I've heard these exact words somewhere else before. Where would I have encountered this exact wording from a document which has been declassified just in the past few days? I dumped the phrase into google and sure enough:

http://www.nsa.gov/public/pdf/tempest.pdf

Here it is in this document about tempest which was declassified 9-27-2007. It contains a lot more about the story in Japan and tempest etc.

And I notice that this document contains what is certainly the redacted paragraph in the other document between the paragraph about the discovery of the antenna and the one that begins "Why, way back in 1954, when the Soviets published a rather comprehensive set of standards..."

This paragraph is about how 40 microphones were found in the US embassy in Moscow and talks about a "large metal grid buried in the cement of the ceiling over the Department of State communications area" and that it had a wire leading off somewhere. Apparently such things were being found as far back as 1953 and the US did not know what their purpose was.

The next paragraph puts the above into context when it says that in 1954 "the Soviets published a rather comprehensive set of standards for the suppression of radio frequency interference". So the previous paragraph reveals some details about what kinds of devices were found but the second paragraph goes on to imply that the Soviets may have been listening in on our unencrypted electronic communications for at least 10 years before the US figured out that it was possible to do so and took action.

It's funny how something which would seem so obvious to us now in hindsight baffled the NSA for at least 10 years. It is also funny that it is possible to reconstruct redacted materials from declassified documents using Google due to the use of cut and paste from a document written back in 1973.