Integrity-based Attacks for Encrypted Databases and Implications.

Inference attacks on property-preserving encrypted databases (e.g., CryptDB) have been previously studied. These demonstrate how in certain scenarios one can recover plain text from databases that provide columnar encryption by using auxiliary information such as column statistics. Newer generation of encrypted databases are now being built using secure enclave technology. In this paper, we first show how the current generation of encrypted databases are robust against these previously published attacks. However, we identify two broad patterns that we identify as query integrity attacks and data integrity attacks that can be used to construct attacks that are similar in scope for a variety of encrypted databases built using enclaves. We believe this paper initiates an important discussion about the need for integrity protection for future encrypted databases.