This document presents a system for secure ranked keyword search over encrypted cloud data. It aims to allow data owners to outsource encrypted data to the cloud while enabling authorized users to efficiently search the data. The system uses an encrypted index and relevance scores to return search results in ranked order based on relevance, without revealing keywords or data contents. It proposes algorithms for building the encrypted index, calculating relevance scores, and mapping values to enable ranked search. The system is designed to achieve security of data and queries while providing efficient search functionality on outsourced encrypted cloud data.
1. International Journal of Research in Advent Technology, Vol.2, No.8, August 2014
E-ISSN: 2321-9637
39
Secure Ranked Keyword Search Over Cloud Data
MS. M. R. GIRME 1, PROF. G.M. BHANDARI 2
ME Computer Engg, 1, 2, JSPM’s BSIOTR, Wagholi, Pune-141, 2,
Email: mayura.shelke@gmail.com1
Abstract- Now a day’s cloud computing becoming so popular due to attractive features of cloud, users are
storing large amount of data on cloud storage, these data may be users personal or secret. After storing data user
can access data any time without any burden of hardware and software. But outsourcing plaintext data is big risk
in cloud. So to protect data privacy data has to be encrypted before outsourced to the cloud and also to retrieve
the data files correctly, introducing ranked keyword search mechanisms. So, in this paper implementing ranked
keyword search over outsourced cloud data.
Index Terms- IAAS, OPSE, PAAS, RSSE, SAAS etc
1. INTRODUCTION
Today the latest paradigm to emerge is that of Cloud
computing provides reliable services delivered
through data centers that are built on virtualized
compute and storage technologies [1][2]. Cloud
Computing becomes more sensitive information are
being centralized into the cloud such as e-mails,
personal health records, company finance data, and
government documents, etc. The fact that data owners
and cloud server are no longer in the same trusted
domain may put the outsourced unencrypted data at
risk the cloud server may be leak data information to
unauthorized entities are hacked. Data encryption
makes effective data utilization is a very challenging
task. Besides, in Cloud Computing, data owners may
share their outsourced data with a large number of
users, who might want to only retrieve certain specific
data files they are interested in during a given session
Such keyword search technique allows users to
selectively retrieve files of interest and has been
widely applied in plain text search scenarios
Unfortunately, data encryption, which restricts user’s
ability to perform keyword search and further
demands the protection of keyword privacy makes
the traditional plaintext search methods fail for
encrypted cloud data.
2. LITERATURE SURVEY
We have done a survey on existing searching methods
Practical Techniques for Searches on encrypted data
(PTSED) [6], Secure Index (SI)[7] and Public key
encryption (PKE)[8] and summarized with following
characteristic [5]. We also compared this study with
our proposed system.
I. Sequential approach
This method will find a particular keyword in a
document, which will check for every one of its
elements, and will display the search result one at a
time and in linear order and this will decrease the
performance i.e for example Searching ”a[a-z]b”
,needs 26 queries.
II. Document Index
Storing a secure keyword index in cloud. This kind of
index will allow a query to check if the documents
contain a keyword and will retrieve the files. It will
not search for the entire document based on index
keyword will retrieve the documents that are
especially useful for large documents and large
document.
III. Perform keywords filter
Indexing of keyword contains unique keywords; it
will not contain the duplicate keywords in index files.
IV. Public Key authentication
This kind of encryption will allow anyone to access
the data in cloud, which is not efficient one.
Table 1. System comparative analysis
Characteristic PTSED SI PKE Proposed
System
Sequential
Approach
Yes No Yes Not
supported.
Document
Index
No Yes No Yes
Keyword
Filter
No Yes No Yes
Secret Key Public No Public Private
Cloud
No No Yes Yes
computing
The following fig.1 shows the comparative analysis of
different systems with proposed system. The proposed
system satisfied most of the characteristics of existing
system.
.
2. International Journal of Research in Advent Technology, Vol.2, No.8, August 2014
E-ISSN: 2321-9637
Characteristic
s Range
Fig 1. System comparative analysis
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
3. PROPOSED SYSTEM
We focus on cloud data storage security. To ensure
the correctness of users’ data in the cloud, we define
and solve the problem of secure ranked keyword
search rch over encrypted cloud data. We explore the
statistical measure approach, i.e. relevance score,
from information retrieval to build a secure searchable
index, and develop a one-to-many order-order
preserving
mapping technique. The resulting design is able to
facilitate efficient server-side ranking without losing
keyword privacy. The new scheme further supports
secure and efficient dynamic operations on data
blocks, including: data update, delete and append.
· Goal and Objectives
The goal of the project is to enable ranked searchable
symmetric encryption for effective utilization of
outsourced and encrypted cloud data under the
aforementioned model; system design should achieve
the security and performance guarantee. The
objectives of the project are as below:
1. Ranked keyword search
To explore different mechanisms for designing
effective ranked search schemes based on the existing
searchable encryption framework.
2. Security guarantee
To prevent cloud server from learning the plain text of
either the data files or the searched keywords, and
achieve the as strong-as-possible security strength
compared to existing searchable encryption schemes.
3. Efficiency
Above goals should be achieved with minimum
communication and computation overhead
4. SYSTEM ARCHITECTURE
We consider an encrypted cloud data hosting service
involving three different entities: data owner, data
user, er, and cloud server as in fig.2
Data owner has a
collection of n data files C= (f1, f2...fn) that he wants
to outsource on the cloud server so, before
outsourcing, data owner will first build a secure
searchable index I from a set of m distinct keywords
W = (w1,w2…wm) extracted from the file collection C,
and store both the index I and the encrypted file
collection C on the cloud server. We assume the
authorization between the data owner and users is
appropriately done. To search the file collection for a
given keyword w, an authorized user generates and
submits a search request in a secret form
Tw of the keyword w to the cloud server. Upon
receiving the search request T
responsible to search the index I and return the
corresponding set of files to the user. We consider the
secure ranked keyword search problem as follows: the
search result should be returned according to certain
ranked relevance criteria.
Fig 2. System architecture [2
· System Modules
1. Encrypted File Outsource/Upload module
In this module owner can upload file to cloud server.
Whole file data is encrypted by server and stored to
server.
2. Keyword Indexing Module
In this module keyword from document will be
extracted and index of such keywords along with the
list of documents which contains keywords. This
index is also encrypted. Index building is done using
below algorithm.
3. User Query module
In this module User searches documents by using
keywords. Relevance score of document is calculated
for searched keywords for documents whose
keywords are matched. Based on this calculated
relevance score, and result will be displayed
according to this relevance score.
4. Document Retrieval module
Finally decrypted document is given to user if
authentication is made between them. Whole process
don only in encrypted
5. DESIGN PROCESS
40
ing, ) ion form—a trapdoor
he Tw, the cloud server is
2]
arches
3. International Journal of Research in Advent Technology, Vol.2, No.8, August 2014
E-ISSN: 2321-9637
The following fig.3 shows design process of
Fig 3. Design process
system.
1. Mathematical Model Design &
Algorithms
· Ranking Function- It is used to calculate
relevance (frequency) score of keyword.
Score (Q, Fd) =ΣtεQ 1/|Fd|.(1+ln f
Parameters
• Q - searched keywords;
• fd,t - TF of term t in file Fd;
• ft - number of files that contain term t;
• N -The total number of files in the
collection;
|.(fd,t) .ln(1+N/ft)
• |Fd| -Length of file Fd,
keyword.[9]
;
· One-to-many Order Preserving Mapping
In the searchable index, for each keyword, every
relevance score will always bind To a specific file ID.
For e.g. index list for keyword “network”
“Network” = F1||1; F2||1; F4|||1; ……………
With file ID as part of seed, for the same plain text,
the cipher text will be randomly selected within the
same interval everytime.So following followin
diagram shows
overview of OPM[10] plain text to cipher text
assignment process. Here plaintext ’m’ is first mapped
to a non-overlapping interval in range, determined by
encryption key. Ciphertext ’c’ is then chosen by using
numerical plain text ’m’ as seed.
Plaintext mapped to random Random chiphertext selection
Sized Non overlapping interval
via seed “1|| F4
Fig 4: OPM algorithm process
· AES Algorithm
AES (Advanced Encryption Standard
symmetric encryption/decryption algorithm
Follo
wing
Fig.5
shows
AES
algorit
hms
struct
ure
for
encry
ption
and
decry
ption.
Encryption
Standard) [11] is a
Fig 5. AES
1
2
.
.
M-1
M
NN
algorithm.
Decryption
41
1
2
3
4
5
.
.
.
N-2
N-1
1
2
3
.
.
.
.
N-2
N-1
N
4. International Journal of Research in Advent Technology, Vol.2, No.8, August 2014
E-ISSN: 2321-9637
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6. RESULT
Fig 6(a). User Registration
Fig 6(b).User Login
Fig 6(c) Searched keyword
Fig 6(e). Upload file
7. CONCLUSION
Cloud computing is one of the current most important
and promising technologies. A data owner can store
his data in cloud and user could retrieve data files
whenever needed. To retrieve data files correctly we
introduce ranked keyword search mechanism. In this
5. International Journal of Research in Advent Technology, Vol.2, No.8, August 2014
E-ISSN: 2321-9637
43
paper we motivate and solve the problem of
supporting efficient ranked keyword search for
achieving effective utilization of remotely stored
encrypted data in Cloud Computing. Then
appropriately weaken the security guarantee, resort to
the newly developed crypto primitive OPSE, and
derive an efficient one-to-many order-preserving
mapping function. For future works, a new scheme
could be developed the authentication of ranked
search results, and the reversibility of our proposed
one-to-many order-preserving mapping technique,
and searching technique for audio and video.
REFERENCES
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[11] http://www.facweb.iitkgp.ernet.in/sourav/AES.pdf