Towards Robust Computation on Encrypted Data

Abstract

Encryption schemes that support computation on encrypted data are useful in constructing efficient and intuitively simple cryptographic protocols. However, the approach was previously limited to stand-alone and/or honest-but-curious security. In this work, we apply recent results on “non-malleable homomorphic encryption” to construct new protocols with Universally Composable security against active corruption, for certain interesting tasks. Also, we use our techniques to develop non-malleable homomorphic encryption that can handle homomorphic operations involving more than one ciphertext.