Quantum Xchange, one of the pioneers in providing commercial quantum key distribution services in the United States, has introduced a new product called Phio™ Trusted Xchange (TX). This system uses an out-of-band symmetric key technique to deliver encryption keys. Because the communication of the keys is separated from communication of the data, the Phio TX’s protection stems from the fact that anyone intercepting the keys and data would need to match up which piece of data goes with which key. That may be an impossible task since these two elements may be transmitted at different times and mixed up with other communications traffic. This system uses a patent pending technology and is different from any of the Post-Quantum Cryptography (PQC) methods that are under review in the NIST competition.
Quantum Xchange views their Phio TX product as complementary to their previously released QKD-based Phio QK system. Because Phio TX uses classical transmission media for communication, this system is not distance limited in the way that QKD transmissions are over fiber optic cable. The Phio QK system does provide unbreakable key distribution that is guaranteed by the laws of quantum mechanics, but for distances greater than 100 km it would need to be supplemented through the use of Phio TX in conjunction with Phio QK. Quantum Xchange does have production customers using Phio QK within their U.S. East Coast network.
Quantum Xchange has provided us with a diagram of their high level architecture which you can see below.
For more information regarding Quantum Xchange’s announcement, you can view the news release on their web site here.
October 4, 2019