Paper 2017/970

A New Functional Encryption for Multidimensional Range Query

Jia Xu, Ee-Chien Chang, and Jianying Zhou

Abstract

Functional encryption, which emerges in the community recently, is a generalized concept of traditional encryption (e.g. RSA and AES). In traditional encryption scheme, decrypting a ciphertext with a correct decryption key will output the original plaintext associated to the ciphertext. In contrast, in functional encryption scheme, decrypting a ciphertext with a correct decryption key will output a value that is derived from both the plaintext and the decryption key, and the decryption output would change when different correct decryption key is used to decrypt the same ciphertext. We propose a new functional encryption scheme for multidimensional range query. Given a ciphertext that is the encryption of some secret plaintext under a public attribute (a multidimensional point), and a decryption key corresponding to a query range and a function key. If the public attribute point is within the query range, a user is able to decrypt the ciphertext with the decryption key to obtain a value, which is the output of a pre-defined \emph{one-way} function with the secret plaintext and the function key as input. In comparison, in previous functional encryption for range query, a decryption will simply output the original secret plaintext when the attribute point is within the query range.