Private Function Evaluation (PFE) is the problem of evaluating one party’s private data using a private function owned by another party. Existing solutions for PFE are based on universal circuits evaluated in secure multiparty computations or on hiding the circuit’s topology and the gate’s functionality through additive homomorphic encryption. These solutions, however, are not efficient enough for practical use; hence there is a need for more efficient techniques. This work looks at utilizing the Intel Software Guard Extensions platform (SGX) to provide a more practical solution for PFE where the privacy of the data and the function are both preserved. Notably, our solution carefully avoids the pitfalls of side-channel attacks on SGX. We present solutions for two different scenarios: the first is when the function’s owner has an SGX-enabled device and the other is when a third party (or one of the data owners) has the SGX capability. Our results show a clear expected advantage in terms of running time for the first case over the second. Investigating the slowdown in the second case leads to the garbling time which constitutes more than 60% of the consumed time. Both solutions clearly outperform FairplayPF in our tests.

中文翻译：

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使用英特尔SGX进行私有功能评估

私有功能评估（PFE）是使用另一方拥有的私有功能评估一方的私有数据的问题。现有的PFE解决方案基于在安全的多方计算中评估的通用电路，或者基于通过加法同态加密隐藏电路的拓扑和门功能的方法。然而，这些解决方案对于实际使用而言不够有效。因此，需要更有效的技术。这项工作着眼于利用Intel Software Guard Extensions平台（SGX）为PFE提供更实用的解决方案，该方案既保留了数据的私密性，又保留了功能。值得注意的是，我们的解决方案谨慎地避免了对新交所进行边信道攻击的陷阱。我们提供了两种不同方案的解决方案：第一个是功能所有者拥有启用了SGX的设备，第二个是第三方（或其中一个数据所有者）具有SGX功能时。我们的结果显示出第一种情况比第二种情况在运行时间方面明显的预期优势。调查第二种情况下的减速会导致花费的时间超过构成时间的60％。在我们的测试中，两种解决方案均明显优于FairplayPF。