Proactive quantum secret sharing

Gan Gao, Yue Wang

김상겸

Huawang Qin, Xiaohua Zhu, Yuewei Dai

A proactive quantum secret sharing scheme is proposed, in which the participants can update their shadows periodically. In an updating period, one participant randomly generates the GHZ states and sends the particles to the other participants, and the participants update their shadows according to the measurement performed on the particles. After an updating period, each participant can change his shadow but the secret is changeless. The old shadows will be useless even if they have been stolen by the attacker. The proactive property is very useful to resist the mobile attacker.

Ri‐Gui Zhou, Xiaoxue Zhang, Lin-Tao Du

Joshua Baron, Karim El Defrawy, Joshua Lampkins +1 more

Proactive secret sharing (PSS) schemes are designed for settings where long-term con-dentiality of secrets has to be guaranteed, specically, when all participating parties may eventually be corrupted. PSS schemes periodically refresh secrets and reset corrupted parties to an uncorrupted state; in PSS the corruption threshold t is replaced with a corruption rate which cannot be violated. In dynamic proactive secret sharing (DPSS) the number of parties can vary during the course of execution. DPSS is ideal when the set of participating parties changes over the lifetime of the secret or where removal of parties is necessary if they become severely corrupted. This paper presents the rst DPSS schemes with optimal amortized, O(1), per-secret communication compared to O(n4) or exp(n) in number of parties, n, required by existing schemes. We present perfectly and statistically secure schemes with near-optimal threshold in each case. We also describe how to construct a communication-ecient dynamic proactively-secure multiparty computation (DPMPC) protocol which achieves the same thresholds.

Huawang Qin, Yuewei Dai