The Zero Hour

Telephone calls that are encrypted or scrambled also tend to pique the NSA’s suspicion.

The same evening that Baumann agreed to work for Malcolm Dyson, a random fragment of a telephone conversation between two points in Switzerland was captured by a geosynchronous Rhyolite spy satellite, moving 22,300 miles above the earth’s surface at the exact speed of the earth’s rotation-in effect, hovering. The conversation was sent over landlines using microwave linkage, via two microwave towers located in Switzerland, in line of sight to each other.

In many areas of the world, topographical concerns-mountains, bodies of water, and the like-make it impossible for telephone conversations to travel exclusively by landlines. So an enormous volume of telephone traffic is beamed between microwave towers. Because each microwave tower sends out its transmission in the shape of a cone, some of the waves continue to travel into the ether, where they can be picked up by satellite.

The captured signal, which contained a fragment of the telephone conversation, was scooped up by a hovering NSA Rhyolite satellite and relayed to another satellite over Australia, thence to a relay site, and then to Fort Meade, where some twenty-seven acres of computers are located deep below the National Security Agency’s Headquarters/Operations Building. It is said to be the most formidable concentration of computational power in the world.

Within minutes, the signal was classified and reconstructed. Only then were a couple of interesting things learned about the captured telephone conversation.

First, the NSA analysts discovered that the signal was digital: it had been converted into a series of zeroes and ones. Digital signals have a great advantage over analog signals in that they are received with maximum clarity.

Digital signals have another advantage over analog. Once scrambled, they are secure, impenetrable, impossible to be understood by anyone outside a handful of government agencies in the most developed countries.

Then the NSA analysts discovered a second interesting thing. The captured conversation had been rendered even more secure from eavesdropping by means of a state-of-the-art digital encryption system. It is not uncommon these days for private citizens-particularly in the world of high finance-to make their most sensitive calls on sophisticated, secure telephones that digitally encrypt their voices so that they can’t be bugged, tapped, or otherwise eavesdropped on.

But the vast majority of suppliers of these secure phones (one of the biggest is Crypto A.G. of Zurich) cooperate with law enforcement by selling their encryption schemes to both the National Security Agency and the British GCHQ (the Government Communications Headquarters, in Cheltenham, England, which is the British counterpart of the NSA). So even most encrypted phone conversations can be listened to by the NSA and GCHQ. International businessmen discussing illegal schemes and drug cartels discussing transactions all tend to speak carelessly over “secure” phones, not realizing that most of them really aren’t secure at all.

But this particular digitally encrypted format was unknown to either NSA or GCHQ. And that was the third peculiar discovery.

The scrambled signal was sent immediately to the Cryptanalytic Division at NSA’s Headquarters/Operations Building. There it was run through a Cray supercomputer, which tested the signal against all known encryption schemes. But the Cray came up blank. The signal wouldn’t break. Instead of voices speaking, there was only a bewildering sequence of ones and zeroes that the computer couldn’t comprehend.

This in itself was extraordinary. The NSA’s computers are programmed with the keys to virtually every known cipher ever invented, every mechanism to encipher that has ever been used. This includes any system ever used by anyone at any time in history, anything ever written about in a technical paper, in a book, even in a novel, any cipher that’s ever been even floated as a hypothesis.

As long as the computers are fed a large enough sample of the cipher, and the encryption scheme is known to the NSA, they will crack the code. Most digital signals are broken immediately. But after minutes, then hours of churning, the computers were stumped.

The NSA abhors the existence of any encryption scheme it doesn’t know. To a cryptanalyst, an “unbreakable” encryption is like an impenetrable safe to a master safecracker, an unpickable lock to a master lockpick. It is a challenge, a taunt, a red flag.

Two cryptanalysts-cryppies, as they’re called within the Fort Meade complex-hunched before a screen and watched with mingled fascination and frustration.

“Jeez, what’s wrong with this one?” George Frechette said to his officemate, Edwin Chu. “Everything’s processing except this one string. Now what?”

Edwin Chu adjusted his round horn-rimmed glasses and peered through them for several moments at the flashing numbers on the screen. “We got us a new one.”