Measurement-device-independent quantum cryptographic conferencing with an untrusted source

Chen Rui-Ke^{1, 2}, Bao Wan-Su^{1, 2, †}, Wang Yang^{1, 2}, Bao Hai-Ze^{1, 2}, Zhou Chun^{1, 2}, Jiang Mu-Sheng^{1, 2}, Li Hong-Wei^{1, 2}

(color online) Secret key rate versus fiber length with different values of . The red dashed curve denotes the asymptotic secret key rate with trusted source in Ref. ^[43]. At short distance, the asymptotic key rates for the two cases (with trusted and untrusted sources) almost overlap. With and considering the imperfections of intensity detector, MDI-QCC with an untrusted source can achieve the nonzero asymptotic secret key rate in long distance approximating to 105 km.