China Communications • June 2015
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and decryption is generally performed by the
software rather than hardware. At the same
time, this encryption method must face the
challenge that many encrypted data entries
may have the same value.
The third data security scheme for data
centers is media level security technology[10],
which is a new method involving static data
encryption on storage equipment such as hard
disks and tapes. Although media-level encryp-
tion provides a high degree of transparency
for users and applications, the protective effect
is very limited because the data has not been
encrypted during transmission. In this scheme,
data will be encrypted only after reaching the
storage device, and media-level encryption can
only guard against the theft of physical storage
media. In addition, use of this technology in a
heterogeneous environment will require use of
multiple key management software, which will
increase the complexity of key management,
thereby increasing the risks for data recovery.
An embedded encryption device is the fourth
security scheme for data centers. Embedded
encryption devices can encrypt the data sent
via them to storage devices, and decrypt the
data that is retrieved. Embedded encryption
devices are a good solution for point-to-point
congurations, but it is difcult to extend, and
the overhead is very large.
The final scheme is application-level data
encryption technology[11]; this technology
is an end-to-end encryption solution. It can
ensure that only certain users get to access
the data through a particular application. This
scheme will be very costly because it must
maintain many parameters and data structures.
As the complexity, variety, and popular-
ity of many advanced information services
grows, data centers has formed the backbone
of these services offered via the Internet in-
cluding load-hosting, e-commerce, social
networking, and a variety of more general
services such as software as a service (SaaS),
platform as a service (PaaS), and other forms
of grid/cloud computing. Of all the advanced
network technology, cloud computing is very
popular and has been a hot issue recently. The
Section V, implementation and simulation of
the related schemes are designed and realized;
we concluded the paper in SectionVI.
II EXISTING SOLUTIONS AND RELATED
WORKS
Data centers play an important role in modern
information systems which always perform
complex computations and retrieve large
amount of datasets from data centers. In a
distributed environment, an application may
needs several datasets located in different data
centers and therefore face some challenges
such as data security, privacy protection and
authentication. In order to enhance the secu-
rity of cloud client data in data centers, some
schemes [4-7] have been proposed, but these
schemes mainly focused on designing some
algorithms to keep data confidential, these
algorithms are always costly and cannot be
applied on big data efciently.
Generally, there are four kinds of conven-
tional security mechanisms to protect data.
The first scheme related to the file-level
data security[8], which can be implemented on
the host. For some applications, this security
method can cause performance problems; at
the same time, it will introduce some limita-
tions for data backup operations, especially
for database backup. In particular, file-level
encryption introduces challenges with respect
to key management and thus causes low ef-
ciency for data centers. Furthermore, le-level
encryption may be inefficient because often
only a small fraction of a le will contain in-
formation that needs to be protected.
The second scheme mainly focused on
database-level data security[9], which can be
applied when the data stored in a database.
This deployment mechanism is known as
column-level encryption in that it encrypts
the data in each column of the database table.
This scheme may be economical for compa-
nies who find that all their sensitive data are
stored on one or two columns of a database.
However, this process will lead to a decline in
system performance because the encryption
Instead of protecting
the big data itself, the
proposed scheme
protects the mapping
of the various data
elements to each pro-
vider using a trapdoor
function.