We consider a quantum and classical version multi-party function computation problem with $n$ players, where players $2, \dots, n$ need to communicate appropriate information to player 1, so that a "generalized" inner product function with an appropriate promise can be calculated. The communication complexity of a protocol is the total number of bits that need to be communicated. When $n$ is prime and for our chosen function, we exhibit a quantum protocol (with complexity $(n-1) \log n$ bits) and a classical protocol (with complexity $(n-1)^2 (\log n^2$) bits). In the quantum protocol, the players have access to entangled qudits but the communication is still classical. Furthermore, we present an integer linear programming formulation for determining a lower bound on the classical communication complexity. This demonstrates that our quantum protocol is strictly better than classical protocols.
翻译:我们考虑一个包含n个玩家的量子与经典版本的多方函数计算问题,其中玩家2至n需向玩家1传递适当信息,从而在特定承诺条件下计算“广义”内积函数。协议的通信复杂度指需要传输的总比特数。当n为素数且对于所选函数,我们展示了一个量子协议(复杂度为(n-1)log n比特)和一个经典协议(复杂度为(n-1)²(log n²)比特)。在量子协议中,玩家可访问纠缠量子比特,但通信仍为经典方式。此外,我们提出了一种整数线性规划方法,用于确定经典通信复杂度的下界。这表明我们的量子协议严格优于经典协议。