Construction for Searchable Encryption with Strong Security Guarantees
István Vajda · International Journal of Computer Network and Information Security · 2019
We present a construction for searchable symmetric encryption (SSE).We consider a wide range of attacks and hardness assumptions and fulfill the strongest security requirements.The "standard" privacy requirement against searchable encryption is message indistinguishability under an adaptively chosen keyword attack (IND-CKA2).We consider to protect the data and the keyword(s) together, i.e. privacy of the data is not considered as a separate problem (as the latter is typical in research papers).Beside the CKA model, we consider also the adaptively chosen trapdoor attack (CTA).Against active attacks (such as swapping attack) we add integrity protection for the (data, keyword) pair.By guaranteeing existential unforgeability (EU) for trapdoor keys we give protection against Keyword Guessing Attack (KGA).Attacks via searching for patterns in the database is prevented by randomized keyword encryption and trapdoor generation.Our construction is secure in the standard model of computation assuming bilinear groups with the widely used Symmetric eXternal Diffie Hellmann (SXDH) assumption.