论文标题
确保NISQ时代的量子计算
Securing Quantum Computations in the NISQ Era
论文作者
论文摘要
最近的实验成就激发了开始感受到古典计算的局限性的公司的不断增长的兴趣。然而,鉴于持续的隐私丑闻,通过远程访问的服务器构成量子计算的未来可用性构成了特殊的挑战:具有量子限制功能的客户希望他们的数据和算法保持隐藏状态,同时能够验证其计算是否正确执行。量子计算的盲人和可验证委托的研究试图解决这个问题。但是,可用的技术不仅遭受高高的开销,而且遭受过度敏感性的影响:在嘈杂的设备上运行时,不完美触发了与恶意攻击相同的检测机制,从而导致永久流产的计算。因此,虽然恶意量子计算机被盲和可验证的协议无害,但固有的噪声严重限制了其可用性。 我们使用有效,健壮,盲目,可验证的方案来解决此问题,以将确定性量子计算委托使用经典的输入和输出。我们表明:1)恶意服务器最多可以用指数级的成功概率作弊; 2)如果有足够小的噪声,该协议成功以指数指数接近1的概率; 3)开销几乎没有一个多项式的初始计算的重复数量,与测试运行交织在一起,在内存和门上需要相同的物理资源; 4)对于某些计算,以测试运行失败的概率来衡量的可忍受噪声量可能高达25%,并且使用平面图资源状态时通常将限制12.5%。关键点是可以在没有通用计算图的情况下提供安全性,并且在我们的设置中,不需要全故障耐受性就可以将置信度呈指数级接近1。
Recent experimental achievements motivate an ever-growing interest from companies starting to feel the limitations of classical computing. Yet, in light of ongoing privacy scandals, the future availability of quantum computing through remotely accessible servers pose peculiar challenges: Clients with quantum-limited capabilities want their data and algorithms to remain hidden, while being able to verify that their computations are performed correctly. Research in blind and verifiable delegation of quantum computing attempts to address this question. However, available techniques suffer not only from high overheads but also from over-sensitivity: When running on noisy devices, imperfections trigger the same detection mechanisms as malicious attacks, resulting in perpetually aborted computations. Hence, while malicious quantum computers are rendered harmless by blind and verifiable protocols, inherent noise severely limits their usability. We address this problem with an efficient, robust, blind, verifiable scheme to delegate deterministic quantum computations with classical inputs and outputs. We show that: 1) a malicious Server can cheat at most with an exponentially small success probability; 2) in case of sufficiently small noise, the protocol succeeds with a probability exponentially close to 1; 3) the overhead is barely a polynomial number of repetitions of the initial computation interleaved with test runs requiring the same physical resources in terms of memory and gates; 4) the amount of tolerable noise, measured by the probability of failing a test run, can be as high as 25% for some computations and will be generally bounded by 12.5% when using a planar graph resource state. The key points are that security can be provided without universal computation graphs and that, in our setting, full fault-tolerance is not needed to amplify the confidence level exponentially close to 1.