Cloud supports only equality search and can’t deal

Cloud
Computing is a model for providing on-demand services like storing and accessing data and programs
over the Internet instead of your computer’s hard drive. With the advantages of
cloud computing, most of the data owners are outsourcing their data base to
cloud for great flexibility and economic savings.

Being provide many benefits cloud storage is
also has privacy concern. Cloud server is protecting by encrypting the data and
keep the secret key with it, but the problem is inside attacker who is curious
to know about the data could access it. General Solution to protect outsourcing
database from un-trusted cloud is by encryption. We could encrypt the database
and place in the cloud. But retrieval of the data becomes a problem which
requires searching over encrypted database. Hence how to design efficient
search over encrypted database is the challenge. Encryption of database before
placing in the cloud give us privacy. But it will limit us search over
encrypted data

Recently several range search over encrypted
data has proposed 1-3, Dan Boneh at al. 1 uses symmetric key encryption where
both keys are similar, but if attacker knew the key he could get all the
information. Elaine Shi at al. 2 provided privacy of the message but the leakage
of attributes takes place. Bellare et al. 3 proposed a
deterministic efficiently searchable public-key encryption scheme. Here they
use searchable tags which could be queried by client to each cipertext. Since
using tag which are searchable server could organised them in sorted order and
provide logarithmic search time. Although it is efficient, this scheme has
several drawbacks. It supports only equality search and can’t deal with
duplicate attributes.

By using Order Preserving Encryption (OPE) can
be efficiently implemented over the range search, but it
complicates handling of duplicate values. OPE is immutable, but for privacy we need it to be mutable Keyword SSE
scheme could provide range search over encrypted data, but if the range is 100
200 , it searches 100,101,102,…..200. It is completely compatible, as it is
comparing each value over encrypted data, but search is inefficient due to
search on large keyword values for given range.