Jacob Weindling, MJLST Staffer
Sending secret messages across the world has traditionally required sending messages that risked interception or eavesdropping by unintended recipients. Letters sent on horseback, telegraphs sent over wires, and radio transmissions through the atmosphere were all theoretically capable of interception in transit between the sender and the receiver. This problem was particularly pronounced in World War II, when the Allies easily intercepted secret Axis transmissions and vice versa. To ensure secrecy the messages were consequently encoded, resulting in seemingly random jumbles of characters to unintended recipients.
Message encoding in World War II operated on two separate principles. For particularly sensitive messages, ‘one-time pads’ were created using (theoretically) random values as starting points. This technique for encryption, while essentially ‘unbreakable’ without access to a copy of the one-time pad, required both the sender and the recipient to hold identical copies of the pads. The second method used machines to transform plaintext messages into code. This second method, famously employed by Nazi Germany’s Enigma machine, substituted true randomness for a complicated but non-random algorithm that provided convenience and reliability. While Enigma proved a sufficient safeguard against traditional pen-and-paper codebreakers, early computers proved adept at quickly defeating the encryption, as dramatically highlighted in “The Imitation Game,” the recent film detailing Alan Turing’s invention of a codebreaking computer during World War II.
Perhaps unsurprisingly, cryptographic systems were added to the State Department’s International Traffic in Arms Regulations (“ITAR”) Munitions List shortly after World War II. Thus, while the U.S. government was severely limited in its ability to shield secret messages from foreign adversaries, it categorized the tools, methods, and development of cryptographic systems as munitions and severely regulated their export to foreign entities. While today the Department of State has narrowed the scope of cryptography to exclude civilian products, regulations remain on specialized military applications. A key assumption of this regulatory regime is that sensitive diplomatic and military information will be transmitted ‘in the clear’ for all who happen to have access to the channel of communications. While today many communications have moved from radio waves to fiberoptic cables, both systems remain vulnerable to surveillance over the air and online.
Last year however, China took a major step toward a vast departure in the philosophy of secret communication. With the launch of the Quess satellite, China hopes to enable quantum entanglement communication between two ground sites. The satellite would in principle transmit a photon to the ground, while retaining a photon that is ‘entangled’ with the released photon. Any changes to the photon on the satellite would thus be reflected in the photon on the ground, serving as a rudimentary method for transmitting binary information. This test comes on the heels of an experiment at Delft University of Technology in the Netherlands, which demonstrated the transmission of information between two electrons separated by a distance of 17 kilometers.
A unique feature of this mode of transmission is that information is not propagated from the sender to the receiver via radio waves, which can be intercepted, but rather via the principle of quantum entanglement. Any attempt to eavesdrop would theoretically be perfectly detectable, as the act of observing the photons being transmitted would potentially change their state and render the communication either unreadable or otherwise obviously tampered with. A system could therefore be developed to automatically cut off communications if disturbances are detected.
Interestingly enough, the U.S. Patent and Trademark Office has granted a patent that describes a similar method for transmitting information via quantum entanglement. The invention, claimed by Zhiliang Yuan and Andrew James Shields on behalf of Toshiba Corporation, was filed with the PTO on September 8, 2006 and published August 7, 2012. This patent builds on prior art that envisioned quantum cryptography, much of which was quietly filed with the PTO during the preceding two decades. Nevertheless, neither Congress nor the Department of State has acted to incorporate any reference to quantum communications into law, perhaps reflecting an unwillingness to address emerging technology that sounds like science fiction, as with self-driving cars and cyberspace before it.
Despite Congress’ history of lethargy in addressing new innovations and the State Department’s regulatory silence on the matter, legislative action or regulation may yet be premature. China has claimed its satellite has successfully sent a ‘hack-proof’ communication from its satellite, but the results have not been studied by the scientific community. Furthermore, no public demonstration has been made of a practical, non-laboratory quantum entanglement communication product. Even if the technology were to be brought to market, any early application will likely have severely low bandwidth by today’s standards, more closely resembling the telegraph than a gigabit internet connection. But with organizations around the world exploring ground- and space-based experiments with quantum communications, the technology appears poised to exit science fiction and enter practical application. Within the next generation, the codebreaking arms race may ultimately become obsolete, and Congress will be faced with a need to address the new secret communication regime.