Semi-quantum key distribution with two classical users

Semi-quantum key distribution (SQKD) is an important research issue which allows one quantum participant equipped with advanced devices to distribute a shared secret securely classical user who has restricted capabilities. In this paper, we propose SQKD protocol two different private keys users respectively at the same time. Alice distributes particle sequences from Bell states Bob and Charlie respectively. Once particles have been processed returned, can simultaneously detect reflected by based on Bell-state measurement generate raw keys. To enable more participants in sharing keys, be extended m + 1 party communication scheme employing -particle GHZ state. large-scale networks, model significantly reduces complexity of compared traditional scheme. Security analyses show that presented free several general attacks, such as entangle-measure attack, modification double CNOT so on.