When coming to perform shortest distance queries on encrypted graph data outsourced in external storage infrastructure such as cloud, a significant challenge is how to compute the shortest distance in an accurate, efficient and secure way. This issue is addressed by a recent work, which makes use of somewhat homomorphic encryption (SWHE) to encrypt distance values output by a 2-hop cover labeling (2HCL) scheme. However, it may import large errors and even yield negative results. Besides, SWHE would be too inefficient for normal clients. In this paper, we propose GENOA, a novel Graph ENcryption scheme for shOrtest distAnce queries. GENOA employs only efficient symmetric-key primitives while significantly enhances the accuracy compared to the prior work. As a reasonable trade-off, it additionally reveals the order information among queried distance values in the 2HCL index. We theoretically prove the accuracy and security of GENOA under rigorous cryptographic model. Detailed experiments on eight real-world graphs demonstrate that GENOA is efficient and can produce almost exact results.

中文翻译：

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启用对加密图数据的隐私保护最短距离查询

在对外包在云等外部存储基础设施中的加密图数据进行最短距离查询时，一个重大挑战是如何以准确、高效和安全的方式计算最短距离。最近的一项工作解决了这个问题，该工作利用某种同态加密 (SWHE) 来加密由 2 跳覆盖标记 (2HCL) 方案输出的距离值。然而，它可能会引入大的错误，甚至产生负面的结果。此外，SWHE 对于普通客户来说效率太低。在本文中，我们提出了 GENOA，一种用于最短距离查询的新型图加密方案。GENOA 仅使用高效的对称密钥原语，同时与之前的工作相比显着提高了准确性。作为一个合理的权衡，它还揭示了 2HCL 索引中查询距离值之间的顺序信息。我们在严格的密码模型下从理论上证明了 GENOA 的准确性和安全性。八个真实世界图形的详细实验表明 GENOA 是有效的，并且可以产生几乎精确的结果。