Events Calendar

EE-EP Seminar - Zheshen Zhang, Friday, January 29th at 2:00pm in EEB 132

Speaker: Zheshen Zhang, Massachusetts Institute of Technology

Talk Title: High-Rate Quantum-Secured Communication

Abstract: The advent of quantum computers will doom public-key cryptography's RSA encryption standard. Quantum key distribution (QKD), however, offers a solution for the post-RSA era: quantum physics' no-cloning theorem can ensure safe creation of one-time pads that permit communication with full information-theoretic security. Prevailing QKD protocols use one-photon-per-bit encoding to be protected by the no-cloning theorem. Propagation loss in long-distance transmission then dramatically reduces their received photon flux, and thus limits their secret-key rates to far less than what will be needed for one-time pad encryption of large files. In this talk, I introduce floodlight quantum-secured communication (FL-QSC), a radically different paradigm that thrives by breaking QKD's one-photon-per-bit barrier. FL-QSC employs many photons per bit, so that propagation loss is mitigated. In addition, it uses a huge number of low-brightness optical modes per bit, to maintain the protection afforded by the no-cloning theorem. We show that no-cloning, plus photon-coincidence channel monitoring, makes the new protocol capable of a 2 Gb/s secret-key rate over a 50-km fiber link. Our initial proof-of-concept experiment, done with 10-dB propagation loss (equivalent to a 50-km fiber link), demonstrated a 52 Mb/s secret-key rate against the optimum collective Gaussian attack. This rate is already a two-orders-of-magnitude improvement over all existing QKD demonstrations. Moreover, FL-QSC could be pushed to the long-sought Gb/s secret-key rates with available equipment, i.e., no new technology need be developed.

Biography: Zheshen Zhang is a Research Scientist in the Research Laboratory of Electronics at MIT. He received the B.S. degree in Electrical Engineering from Shanghai Jiao Tong University in June 2006 and the Ph.D. degree in Electrical and Computer Engineering from the Georgia Institute of Technology in December 2011. He joined MIT in March 2012 as a Postdoctoral Associate. Dr. Zhang's research covers a wide swath of the theoretical and experimental aspects of quantum communications, quantum sensing, and novel materials for scalable quantum information processing platforms.


Host: EE-EP

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 132

Audiences: Everyone Is Invited

Contact: Marilyn Poplawski