Abstract— The use
of Cloud Computing (CC) has increased rapidly in many institutions. Few of the
advantages of CC is cloud data storage, where the customers do not have to
store their data on their remote servers, but the data is stored on the cloud
service provider’s (CSP) side. To this end, security in Cloud computing is
taken to be one of the most important aspects due to the sensitive and
confidential information stored in the remote database(cloud) by the users.
This paper signifies a model to securely store information into the cloud in a
manner that preserves data confidentiality, integrity and ensures availability.
Our approach ensures the security and privacy of client sensitive information
by storing data across single cloud, using a secret sharing approach that uses
Shamir’s secret sharing key algorithm. The model avoids an unauthorized access
and reduces the consequences of encryption techniques. Connection on the user’s device, which will
eliminate excess usage of the mobile data of the user.



Index Terms— electronic health record, cloud computing,
security, double encryption, secret-sharing scheme



I.  Introduction

With technology being the integral
and the most widely used part of the society, more uses and applications of the
same are searched and implemented in various sectors and being searched. The
sectors of the society that benefit the most from new developments in the field
of science is the medical sector. Unfortunately, there are many areas in which
the health sector is lacking dude to evolution of various disease for which
treatments need to be sought. Many a times there are cases which are different
from the common studied cases which need to seek for proper help.

medical sectors have made a huge progress from the current technology at use
and many improvements are being made in it every second. Many a times, there
are situations in which a patient cannot find help from the institution he is
being treated from, and can suffer a huge loss if not treated in time only
because his details were not shared to the respected person.

 Also there are situations in which there is a
loss of data because of manual interpretation of the same and is not stored
properly. The health record of the individual patient is the most essential
part f his treatment and should be properly stored and shared with the proper

In the current situation it is essential and
also very easy to access everything through the net and it also becomes very
feasible for quick sharing and accessing information, but the backdrop of such
a system is the issue of security which can render important and the most
crucial information of any person in danger and what is more important than a
person’s health.




The major aim of the
system is the security aspect of the cloud computing. Data and information will
be shared from one institute to another user without any restriction or hacks.
Cloud user will avoid use of untrusted cloud service provider for use of
medical report from hacker or malicious insiders 1.

Another major objective is to ensure that data
is stored on multi provider cloud to ensure data recovery and security 1.

 While making the cloud secure,
the following objectives are to be met, the cloud computing solution must meet
the basic security and privacy needs of any individual or user deploying it.
The privacy of the cloud and the data security of applications must be
maintained as that is deployed in cloud computing environment. A cloud service
has to maintain data Integrity service Availability.






The proposed system may have a
wide scope of application. The cloud platform provided to all medical
institutes would ensure safety of all the heath records of the patients
involved and also sharing of the health records if necessary would be doubly
secure with the use of shamir’s secret sharing algorithm which ensures secret
key exchange before sharing and also AES algorithm will be applied which will
ensure encryption at the time of the data storage 1.

Secret key algorithm provides
secure database that will prevent security risks.   Also AES algorithm will be made use to give
more security to the data stored in the cloud .this concept will make sure that
the stored data is doubly safe .Shamir’s Secret Sharing algorithm is applied in
cloud which helps to reduce risks of data intrusion and service availability
for ensuring data.

the data records of the patients stored will be stored on various cloud
providers to ensure recovery and faster access if and when the data is lost.


3.       EXISTING


The current system is a single cloud based website
which has a simple authentication system, which can be easily accessed and
hacked. Privacy issues are not addressed adequately at the technical level and
efforts to keep patients data secure have often fallen vulnerable. The storage
privacy in existing system is weaker form of privacy because it does not hide
search and access patterns and systems assuring privacy and security to
safeguard personal health information.

Managing health data is a tedious task. Storing this data on cloud would
resolve the issues and will reduce the maintenance cost. The existing solutions
to ensure data privacy by data encryption is not sufficient just because the
data has been encrypted the user’s information can’t be changed in virtual
machines of cloud providers. Administrator assume that if the data is processed
and collected from different client then the data encryption cannot ensure
privacy in cloud 1.


II.  Description

The proposed system is going to be one where
a multi cloud platform is provided to n number of user, where there is going to
one admin who is given the responsibilities to manage the users and manage the
keys to encrypted text. The users will deal with the front end of the system,
where the basic usage of the proposed system will be storing and sharing of
EHR’s of patients. EHR’s can vary from text to image and sound formats, which
will be stored in data bases across the various clouds.


 At the
time of uploading files in the cloud, the cloud will process an encryption
algorithm on the file which will be AES algorithm, and soon after that the AES
cipher is generated, the cipher text will be passed along with the ids of the
process to the Shamir’s Secret key generation algorithm to generate another key
which stored in the data base


During the sharing of these EHR’s the keys
which are generated will be shared with user to whom the original user has
given the downloading rights to, the user will hence pass the keys to the
decryption function and will be able to download the file if the key is correct


FIG 2.1:-  Proposed Architecture




AES algorithm :

The working of the proposed includes the AES algorithm which
is a standard alortim used for encryption and decryption. The important feature
of this algorithm is that it encrypts the entire file or data in forms of
blocks of 128,192 or 256 bits.


Shamirs secret
sharing algorithm :

Shamir’s secret sharing, there is a distribution a secret
among a group of n participants, each of whom is allocated a part of secret.
The strong point of this method is that the secret can be reconstructed only if
a predefined number of shares are clubbed together, individual shares are of no
use on their own, so anyone with less shares has no extra information about the
secret than someone that has 0 shares