A hidden vector encryption scheme (HVE) is a derivation of identity-based encryption, where the public key is actually a vector over a certain alphabet. The decryption key is also derived from such a vector, but this one is also allowed to have ``$\star$'' (or wildcard) entries. Decryption is possible as long as these tuples agree on every position except where a ``$\star$'' occurs. These schemes are useful for a variety of applications: they can be used as building block to construct attribute-based encryption schemes and sophisticated predicate encryption schemes (for e.g. range or subset queries). Another interesting application -- and our main motivation -- is to create searchable encryption schemes that support queries for keywords containing wildcards. Here we construct a new HVE scheme, based on bilinear groups of prime order, which supports vectors over any alphabet. The resulting ciphertext length is equally shorter than existing schemes, depending on a trade-off. The length of the decryption key and the computational complexity of decryption are both constant, unlike existing schemes where these are both dependent on the amount of non-wildcard symbols associated to the decryption key. Our construction hides both the plaintext and public key used for encryption. We prove security in a selective model, under the decision linear assumption.
|Place of Publication||Enschede|
|Publisher||Centre for Telematics and Information Technology (CTIT)|
|Number of pages||13|
|Publication status||Published - 8 Apr 2010|
|Name||CTIT Technical Report Series|
|Publisher||Centre for Telematics and Information Technology, University of Twente|
- Pairing Based Cryptography
- Hidden Vector Encryption
- Searchable Encryption
Sedghi, S., van Liesdonk, P., Nikova, S. I., Hartel, P. H., & Jonker, W. (2010). Searching Keywords with Wildcards on Encrypted Data. (CTIT Technical Report Series; No. TR-CTIT-10-14). Enschede: Centre for Telematics and Information Technology (CTIT).