DARPA Quantum Network

[1] It became fully operational on October 23, 2003 in BBN's laboratories, and in June 2004 was fielded through dark fiber under the streets of Cambridge and Boston, where it ran continuously for over 3 years.

In year 4, BBN added a second freespace link to the overall network, using nodes created by Qinetiq, and investigated improved QKD protocols and detectors.

Finally, in year 5, BBN added the world's first superconducting nanowire single-photon detector to the operational network.

[5][6] It was created by a collaboration between researchers at BBN, the University of Rochester, and the National Institute of Standards and Technology; that first 100 MHz system ran 20x faster than any existing single-photon detector at telecom wavelengths.

[7][8] In that final year, BBN also collaborated with researchers at the Massachusetts Institute of Technology to implement, and experiment with, a proof-of-concept version of the world's first quantum eavesdropper (Eve).

Error correction was implemented by a BBN variant of the Cascade protocol, or the BBN Niagara protocol which provided efficient, one-pass operation near the Shannon limit via forward error correction based on low-density parity-check codes (LDPC).