IT | Choosing Suitable Security Algorithms for Cloud Computing
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IT | Choosing Suitable Security Algorithms for Cloud Computing

By Mrunalini Motilal Shete and Pragati Damodar Hipparkar
 Department of Computer Engineering, 
Sahakar Maharshi Shankarrao Mohite-Patil Institute of Technology & Research, India

IT | Choosing Suitable Security Algorithms for Cloud Computing

In this article, the encryption algorithms have been proposed to make cloud data secure, vulnerable and gave concern to security issues, challenges and also comparisons have been made between AES, DES and RSA algorithms to find the best one security algorithm, which has to be used in cloud computing for making cloud data secure and not to be hacked by attackers.

RSA Algorithm

The most common Public Key algorithm is RSA, named for its inventors Rivest, Shamir, and Adleman (RSA). RSA is basically an asymmetric encryption and decryption algorithm. It is asymmetric in the sense, that here public key distributed to all through which one can encrypt the message and private key which is used for decryption is kept secret and is not shared to everyone.

How RSA is going to work in cloud environment is explained as: RSA algorithm is used to ensure the security of data in cloud computing. In RSA algorithm we have encrypted our data to provide security. The purpose of securing data is that only concerned and authorized users can access it. After encryption data is stored in the cloud. So that when it is required then a request can be placed to cloud provider. Cloud provider authenticates the user and delivers the data to user. As RSA is a Block Cipher in which every message is mapped to an integer. In the proposed cloud environment, Public key is known to all, whereas Private Key known only to user who originally owns the data. Thus encryption is done by the cloud service provider and decryption is done by the cloud user or consumer. Once the data is encrypted with the Public key, it will be decrypted using the corresponding Private Key only.

AES Algorithm

Advanced Encryption Standard (AES), also known as Rijindael is used for securing information. AES is a symmetric block cipher that has been analyzed extensively and is used widely now-a-days. How AES works in cloud environment? AES, symmetric key encryption algorithm is used with key length of 128-bits for this purpose. As AES is used widely now-a-days for security of cloud. Implementation proposal states that First, User decides to use cloud services and will migrate his data on cloud. Then User submits his services requirements with Cloud Service Provider (CSP) and chooses best specified services offered by provider. When migration of data to the chosen CSP happens and in future whenever an application uploads any data on cloud, the data will first encrypted using AES algorithm and then sent to provider. Once encrypted, data is uploaded on the cloud, any request to read the data will occur after it is decrypted on the users end and then plain text data can be read by user. The plain text data is never written anywhere on cloud. This includes all types of data. This encryption solution is transparent to the application and can be integrated quickly and easily without any changes to application. The key is never stored next to the encrypted data, since it may compromise the key also. To store the keys, a physical key management server can be installed in the user’s premises. This encryption protects data and keys and guarantees that they remain under user’s control and will never be exposed in storage or in transit. AES has replaced the DES as approved standard for a wide range of applications.

DES Algorithm

The Data Encryption Standard (DES) is a block cipher. It encrypts data in blocks of size 64 bits each. That is 64 bits of plain text goes as input to DES, which produces 64 bits of cipher text. The same algorithm and key are used for encryption and decryption, with minor differences. The key length of this algorithm is 56 bits; however a 64 bits key is actually input. DES is therefore a symmetric key algorithm.


Encryption algorithms play an important role in data security on cloud and by comparison of different parameters used in algorithms, it has been found that AES algorithm uses least time to execute cloud data. DES algorithm consumes least encrypt-ion time. RSA consumes longest memory size and encryption time.

By doing implementation for all algorithms in IDE tool and JDK 1.7, the desired output for the data on cloud computing has been achieved. In today’s era demand of cloud is increasing so the security of the cloud and user is on top concern. Hence, proposed algorithms are helpful for today’s requirement. In future several comparisons with different approaches and results to show effectiveness of proposed framework can be provided. 

Publication Details:

This article is an excerpt from a technical paper titled - "Data Secure in Cloud Computing Using Encryption Algorithms", published at International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Index Copernicus Value (2013): 6.14 | Impact Factor (2013): 4.438 Volume 4 Issue 3, March 2015 Licensed Under Creative Commons Attribution CC BY