Puzzle History: Codebreaking and the NSA, part 3

[Image courtesy of NSA’s official Twitter account.]

At the end of part 2 in our series, we left off during the early days of the NSA, as American cryptographers continued to labor under the shadow of the Black Friday change in Russian codes.

You may have noticed that part 2 got a little farther from puzzly topics than part 1, and there’s a reason for that. As the NSA evolved and grew, codebreaking was downplayed in favor of data acquisition. The reasons for this were twofold:

1. Context. You need to understand why given encrypted information is important in order to put it toward the best possible use. As Budiansky stated in part 1, “The top translators at Bletchley were intelligence officers first, who sifted myriad pieces to
assemble an insightful whole.”

2. Russian surveillance and bugging continued to grow more clever and sophisticated, pushing attention away from codebreaking. After all, what good is breaking codes or developing new ones if they can just steal unencrypted intel firsthand by monitoring
agents in the field?

Moving forward, the NSA would continue to pursue all manner of data mining, eventually leaving behind much of the codebreaking and analysis that originally formed the backbone of the organization. But that was in years to come. Cryptography was still a major player in NSA operations from the ’50s and onward.

[The progression of “secret” and “top secret” code words.
Image courtesy of NSA’s official Twitter account.]

In May 1956, NSA cryptanalytic veterans pushed a proposal titled “Recommendations for a Full-Scale Attack on the Russian High-Level Systems,” believing that specially designed computers from IBM could provide the key for cracking the impenetrable Russian cryptography wall. Some cryptographers believed that ever-increasing processor speeds would eventually outpace even sophisticated codes.

By 1960, the NSA had spent $100 million on computers and analytical tools.

The problem? The NSA was collecting so much information that their increasingly small team of cryptoanalysts couldn’t dream of processing even a tiny portion of it.

But the quest for data access would only grow more ambitious.

In the wake of Sputnik’s launch in October of 1957, US signals intelligence would go where no man had gone before. The satellite GRAB, launched alongside Transit II-A in June of 1960, was supposedly meant to study cosmic radiation. (GRAB stood for Galactic Radiation and Background.)

[Image courtesy of NSA’s official Twitter account.]

But it was actually intended to collect radar signals from two Soviet air-defense systems. This was the next step of ELINT, electronic intelligence work. (The younger brother of SIGINT.)

The NSA would later find a huge supporter in President Lyndon Johnson, as the president was heavily invested in SIGINT, ELINT, and any other INTs he could access. This did little to quell the intelligence-gathering rivalry growing between the CIA and NSA.

Of course, that’s not to say that the NSA ceased to do any worthwhile work in codebreaking. Far from it, actually.

During the Vietnam War, NSA analysts pored over North Vietnamese signals, trying to uncover how enemy pilots managed to scramble and respond so quickly to many of the US’s airstrikes conducted during Operation Rolling Thunder.

Careful analysis revealed an aberrant character (in Morse code) in messages that appeared in North Vietnamese transmissions before 90 percent of the Rolling Thunder airstrikes. By identifying when the enemy used that aberrant character, the analysts
were able to warn US pilots whether they were heading toward a prepared enemy or an unsuspecting one during a given sortie.

Other NSA teams worked to protect US communications by playing the role of an enemy analyst. They would try to break US message encryptions and see how much they could learn from intercepted US signals. Identifying flaws in their own procedures — as well as members of the military who were cutting corners when it came to secured communications — helped to make US communications more secure.

[Image courtesy of NSA.gov.]

In 1979, Jack Gurin, the NSA’s Chief of Language Research, wrote an article in the NSA’s in-house publication Cryptolog, entitled “Let’s Not Forget Our Cryptologic Mission.” He believed much of the work done at the agency, and many of the people
hired, had strayed from the organization’s core mission.

The continued push for data acquisition over codebreaking analysis in the NSA led to other organizations picking up the slack. The FBI used (and continues to use) codebreakers and forensic accountants when dealing with encrypted logs from criminal organizations covering up money laundering, embezzlement, and other illegal activities.

And groups outside the government also made impressive gains in the field of encryption, among them IBM’s Thomas J. Watson Research Center, the Center for International Security and Arms Control, and even graduate student programs at universities like MIT and Stanford.

For instance, cryptographer Whitfield Diffie developed the concept of the asymmetric cipher. Joichi Ito explains it well in Whiplash:

Unlike any previously known code, asymmetric ciphers do not require the sender and receiver to have the same key. Instead, the sender (Alice) gives her public key to Bob, and Bob uses it to encrypt a message to Alice. She decrypts it using her private key. It no longer matters if Eve (who’s eavesdropping on their conversation) also has Alice’s public key, because the only thing she’ll be able to do with it is encrypt a message that only Alice can read.

This would lead to a team at MIT developing RSA, a technique that implemented Diffie’s asymmetric cipher concept. (It’s worth noting that RSA encryption is still used to this day.)

[Image courtesy of Campus Safety Magazine.com.]

The last big sea change in encryption came when the government and military realized they no longer had a monopoly on codebreaking technology. Increased reliance and awareness of the importance of computer programming, greater access to computers with impressive processing power, and a groundswell of support for privacy from prying government eyes, led to dual arms races: encryption and acquisition.

And this brings us to the modern day. The revelations wrought by Edward Snowden’s leak of NSA information revealed the incredible depth of government data mining and acquistion, leading some pundits to claim that the NSA is “the only part of government that actually listens.”

Whatever your feelings on Snowden’s actions or government surveillance, there is no doubt that the National Security Agency has grown and changed a great deal since the days of cracking the ENIGMA code or working with the crew at Bletchley Park.

Where will American codebreaking go next? Who knows? Perhaps quantum computing will bring codes so complicated they’ll be impenetrable.

All I know is… it’s part of puzzle history.

I hope you enjoyed this multi-part series on the history of 20th-century codebreaking in America. If you’d like to learn more, you can check out some of the valuable sources I consulted while working on these posts:

Code Warriors: NSA’s Codebreakers and the Secret Intelligence War Against the Soviet Union by Stephen Budiansky

Whiplash: How to Survive Our Faster Future by Joichi Ito

The Secret Lives of Codebreakers by Sinclair McKay

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The Story Behind Bletchley Park

It’s amazing when you consider the impact one of the most common forms of puzzle solving, cryptography, has had on world history. From the Revolutionary War to World War II, codebreaking was a battlefront as crucial and as exhausting as any contested piece of land on the map.

This was brought into stark clarity recently when I read The Secret Lives of Codebreakers by Sinclair McKay, which chronicles the work and lives of the team members at Bletchley Park who dedicated themselves to cracking the German Enigma code. It’s been said that Bletchley Park’s achievements shortened the war by two or three years. That’s no small feat.

(You know the decryption work done at Bletchley Park was good if it inspired parts of two of Ian Fleming’s James Bond novels. The film The Imitation Game barely scratched the surface.)

From The Secret Lives of Codebreakers:

Here, in these grounds fifty miles to the north of London, they would be introduced to the gravest secret of the war. Every intercepted enemy message — every signal from every captain, commander, military division, battleship, U-boat — all these encrypted communications, jumbled up into seemingly random letters in groups of four and five, and transmitted by radio, were gathered by the many listening posts around the British coastline.

From the Battle of Britain to the Blitz, from Cape Matapan to El-Alamein, from Kursk to the V-1 flying bombs, to D-Day and Japan, the work of Bletchley Park was completely invisible, yet right at the heart of the conflict. It was a key player whose presence, at all times, had to be kept utterly hidden from the enemy.

Imagine working these incredibly intensive sessions, obsessively looking over bits of code for hours at a time, knowing that the fate of the world rested on your shoulders, and a simple transcription mistake could cost lives. It’s a mind-boggling concept.

And the book shed a great deal of light on the decryption work itself. For instance, I had no idea how many variations of the Enigma code they were expected to crack.

The German rule was that no message should be more than 250 letters in length; if it was necessary to send a longer message, it should be split into multiple parts. This was designed to make life more difficult for codebreakers: the longer the message, the easier it might be for such a person to see patterns of letters forming among the apparent chaos.

Thanks to preambles in each Enigma message, codebreakers could at least be organized under different color keys: yellow, green, red, and blue. When they ran out of colors, they named keys after marine life, then birds, then elephants, then insects.

This was a war, and organization was key, no pun intended.

The first big break is known as the Herivel Tip, when one of the Bletchley Park crew deduced that some Enigma machine operators might choose the new day’s settings based on the letters used the previous day. This became a valuable jumping-off point for daily decryption attempts with their own coding device, the bombe machine.

In 1941, the first major Enigma-style code, the Abwehr code, was broken by Bletchley Park. In June of 1941, they broke the Vulture key, which revealed German activity on the Eastern front.

But the Germans were constantly adapting and refining their codes. German paranoia led to submarines using a different code than surface naval vessels. So “Dolphin,” the surface naval code, was not the only code troubling Bletchley Park. “Shark,” the submarine key, was a new concern. Thankfully, when U-559 sank in 1942 and its crew abandoned ship, its Enigma machine and a book of current “Shark” keys was salvaged by Allied forces without German knowledge.

In 1943, they broke “Porcupine,” giving them access to all German air force messages for a few weeks.

Around this time, the German High Command began using another method to transmit encrypted messages, and this became yet another focus of Bletchley Park. The “Fish” or “Tunny” communications were between generals and the Fuhrer himself.

This led to the development of the big brother of the bombe machine, Colossus, which combined the logic engines of a Turing machine with electronic valves that allowed it to read 5000 characters a second, five times faster than the previous top machine.

(While this was going on, Turing himself was developing a new speech encipherment system, Delilah, so named because she was a deceiver of men.)

In January 1945, efforts were still going strong, as Bletchley Park not only cracked the “Puffin” and “Falcon” keys of the German army, but effectively countered attempts by the Luftwaffe to implement new encryptions. By this point, dozens of variations of Enigma had been unraveled by the team.

Of course, decryption wasn’t the only thing accomplished at Bletchley Park.

The grand deception that led to the Normandy invasion was also managed there. They gradually fed false data to German Intelligence about military groups like the First United States Army Group preparing to enter France via the Pas de Calais and the Twelfth British Army into Scandinavia and Turkey. This allowed for D-Day to proceed, as German attention was diverted.

But The Secret Lives of Codebreakers goes beyond their wartime victories. McKay takes us behind the scenes of Bletchley Park to share not only the hard-won achievements of the cryptographers there, but also what daily life was like on the isolated estate. From living conditions and several romances to rivalries and petty feuds caused by high tensions, the book catalogues the realities of such stressful work in richly detailed fashion.

I think my favorite discoveries were related to the off-time of the recruits:

Oliver and Sheila Lawn have especially fond memories of the way that Bletchley-ites contrived to use their leisure time: “There was music,” says Mr. Lawn, “Play readings. And play actings. Quite a bit of amateur dramatics. And concerts of all kinds.”

Highland dancing, madrigals, creating palindromes…they were offered all sorts of activities to help keep spirits up after grueling decryption sessions. Certain musical artists were even invited up to perform there!

When you consider how important their work was and how many years they were sworn to silence about Bletchley Park, these revelations become all the more stunning. This isn’t just a fascinating work of puzzle history, this is history itself.

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