Searching Keywords with Wildcards on Encrypted Data
Sedghi, S. and Liesdonk, Peter van and Nikova, Svetla and Hartel, Pieter and Jonker, Willem (2010) Searching Keywords with Wildcards on Encrypted Data. [Report]

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Abstract:  A hidden vector encryption scheme (HVE) is a derivation of identitybased 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 ``'' (or wildcard) entries. Decryption is possible as long as these tuples agree on every position except where a ``'' occurs. These schemes are useful for a variety of applications: they can be used as building block to construct attributebased 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 tradeoff. 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 nonwildcard 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. 
Item Type:  Report 
Faculty:  Electrical Engineering, Mathematics and Computer Science (EEMCS) 
Research Group:  
Link to this item:  http://purl.utwente.nl/publications/70901 
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