An Efficiently Searchable Encrypted Data Structure for Range Queries
This work addresses security vulnerabilities in encrypted databases for users needing efficient range queries, offering a practical solution with minimal performance impact.
The paper tackles the problem of attacks on efficiently searchable encryption by presenting an encrypted data structure that is provably secure against chosen plaintext attacks, achieving a search time overhead of only 10 milliseconds compared to non-secure search.
At CCS 2015 Naveed et al. presented first attacks on efficiently searchable encryption, such as deterministic and order-preserving encryption. These plaintext guessing attacks have been further improved in subsequent work, e.g. by Grubbs et al. in 2016. Such cryptanalysis is crucially important to sharpen our understanding of the implications of security models. In this paper we present an efficiently searchable, encrypted data structure that is provably secure against these and even more powerful chosen plaintext attacks. Our data structure supports logarithmic-time search with linear space complexity. The indices of our data structure can be used to search by standard comparisons and hence allow easy retrofitting to existing database management systems. We implemented our scheme and show that its search time overhead is only 10 milliseconds compared to non-secure search.