Ananth Raghunathan : 2013 Security Workshop


Monday, April 15, 2013
Location: Fisher Conference Center, Arrillaga Alumni Center

"Searching on Encrypted Data without Revealing the Search Predicate."


Starting with the work of Boneh et al. (EUROCRYPT '04) the past decade has seen extensive work on public-key encryption schemes that allow searching on encrypted data. Such schemes have applications in payment gateways that route transactions differently based on the type of transaction. They also have a similar application in systems that filter and forward encrypted emails. Typically, in such a scheme, the secret key holder can construct special tokens that allow anyone to test whether a ciphertext has a particular underlying plaintext (or more generally, whether the plaintext satisfies a particular predicate).

Due to the public-key nature of the encryption scheme, previous efforts ruled out the possibility of protecting the predicate used to construct a token as an adversary may try to learn the predicate by encrypting arbitrary plaintexts of his choice. However, a security notion that captures predicate privacy is easily motivated by considering the payment gateway scenario where the predicate itself might contain sensitive information.

In this work, we show that it is possible to define a security notion protecting predicate privacy and we construct the first public-key searchable encryption schemes that satisfy this notion.


Ananth Raghunathan is a PhD candidate in Computer Science advised by Prof. Boneh. His research focuses on constructing novel cryptographic schemes. His recent work includes constructing better deterministic encryption, searchable encryption, encryption schemes that enable deduplication of data, and encryption schemes that enable efficient key updates. His interests broadly span cryptography and security.