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European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 05
May 2019
Available online: https://ejbss.org/ P a g e | 1608
A Review Paper on Data Encryption & Decryption
Raveena #1
, Preeti #2
1Department of Computer Science
Hindu College of Engineering (HCE),
Deenbandhu Chhotu Ram University of Science & Technology (DCRUST), Sonepat
1
raveenadalal987@gmail.com
2Department of Computer Science
Hindu College of Engineering (HCE),
Deenbandhu Chhotu Ram University of Science & Technology (DCRUST), Sonepat
2preetianeja2005@gmail.com
Abstract— Cryptography is the art of achieving security by encoding messages to make them non-readable. It
is the technique for hiding data and information from unauthorized users. When we send simple message from
one location to another then this message called plain text is visible to anybody. If we want to codify the
message called cipher text so that no one can easily understand the meaning of message then we use
cryptography techniques. There are numerous applications where this technology is used such as ATM pin,
Password, Credit Card number or any other secret communication. Cryptography can be divided into following
three categories depending upon the types of key used: secret key (symmetric) cryptography, public key
(asymmetric) cryptography and hash functions. In this paper we provide review of various types of
cryptography techniques.
Keywords— Cryptography, plain text, cipher text, cryptanalyst
I. INTRODUCTION
Cryptography, then, not only protects data from theft or alteration, but can also be used for user authentication.
Cryptography can be divided into following three categories depending upon the types of key used: secret key
(symmetric) cryptography, public key (asymmetric) cryptography and hash functions. The rapid continuous
increase in exchange of multimedia data over protected and unprotected networks such as the worldwide
available internet and local networks such as shared networks and local area networks etc has encouraged
activities such as unauthorized access, illegal usage, disruption, alteration of transmitted and stored data. This
widely spread use of digital media over the internet such as on social media, on cloud storage systems etc and
over other communication medium such as satellite communication systems have increased as applications and
need for systems to meet current and future demands evolved over the years.
Security concerns with regards to such data transmission and storage has been a major concern of both the
transmitters and receivers and hence the security of critical cyber and physical infrastructures as well as their
underlying computing and communication architectures and systems becomes a very crucial priority of every
institution.
Cryptography is the fundamental platform in which modern information security, which involves the use of
advanced mathematical approaches in solving hard cryptographic issues, has gained its grounds in the digital
world. This has evolved from classical symmetric, in which shifting keys are normally used as well as
substitution methods, ciphers to modern public key exchange cryptosystems, which aims to make cryptanalysis
a difficult approach to deciphering ciphers.
In cryptography there are some important terms and are given below (figure 1):
▪ Plaintext: It is the original text which has to be encrypted.
▪ Cipher text: It is the encrypted text. The text obtain after encoding the data with the help of a key is known as
cipher text.
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European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 05
May 2019
Available online: https://ejbss.org/ P a g e | 1609
▪ Key: It is a word or value that is used to encrypt the plain text or decrypt the cipher text.
▪ Encryption: The method of converting the data into coded form with the help of key is called encryption [4].
▪ Decryption: The method of converting the encoded data to the original form is called decryption.
▪ Crypto Analyst: A crypto analyst is a person who is an expert in analyzing and breaking codes [3].
Figure 1: Cryptographic Model [2]
When we send simple message from one location to another then this message called plain text is visible to
anybody. If we want to codify the message called cipher text so that no one can easily understand the meaning
of message then we use cryptography techniques. The work presented in this paper is to study the existing
encryption algorithm used for data security.
II. LITERATURE SURVEY
There are huge amount of work done by the various researchers in the field of cryptographic algorithm for data
security. Some of these work done by the researchers are explain in this chapter.
Neal Koblitzet al. [4] proposed an elliptic curve cryptosystems for protecting the communication in unsecure
network. Elliptic curves over finite fields of public key cryptosystems use the multiplicative group of a finite
field. These elliptic curve cryptosystems were more secured because the analog of the discrete logarithm
problem on elliptic curves harder than the classical discrete logarithm problem. Limitation of this scheme it was
mainly based on the structure either of the multiplicative group or the multiplicative group of a finite field.
Hugo Krawczyk et al. [5] worked on the order of encryption and authentication scheme for protecting the
communications. They composed a symmetric encryption and authentication scheme for building secured
channels for the protection of communications over insecure networks. They also proved that the other method
of composing encryption and authentication which includes the authentication encryption method was not so
much secured against random attackers. Limitation of this was only forty bit key size can use in this scheme.
Laurent Eschenauer et al. [6] proposed a key based scheme for distributed sensor networks. Key management
scheme designed to satisfy both operational and security requirements of distributed sensor networks. This
scheme requires cryptographic protection of communications, sensor capture detection, key revocation and
sensor disabling. So they present a key management scheme designed to satisfy both operational and security
requirements of distributed sensor networks.
Jung.Wen Lo et al. [7] proposed an efficient key management scheme in a large leaf class hierarchy for access
control. In which users were divided this into different security classes. They also proposed a new key
assignment scheme for controlling the access right in a large partially ordered set hierarchy and reduce the
required computation for key generation. Information retrieval and the number of leaf classes which were
substantially larger than the number of non leaf classes.
Bharat B. Madan et al. [8] worked on various methods used for modelling and quantifying the security attributes
of intrusion tolerant systems. Various issues related to quantifying the security attributes of an intrusion tolerant
system were also addressed. Response of a security intrusion tolerant system to an attack was modelled as a
random process. They facilitate the use of stochastic modelling techniques to predict the attacker behaviour.
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European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 05
May 2019
Available online: https://ejbss.org/ P a g e | 1610
Tariq Jamil et al. [9] worked upon Rijndael method/algorithm for protecting sensitive unclassified government
information. This algorithm was the new advanced encryption standard algorithms recommended by the US
national institute of standards and technology. The performance of Rijndael algorithm based on speed of
encryption, decryption process and keyset up time.
Ho Won Kim et al. [10] worked on Design and Implementation of a private and public key crypto processor and
its application for security system. They present the design and implementation of a crypto processor. This
special purpose microprocessor optimized for the execution of cryptography algorithms. This crypto processor
can be used for various security applications such as storage devices, embedded systems, network routers,
security.
Prosanta Gopeet al. [11] proposed a new block cipher cryptographic symmetric key algorithm named TACIT
encryption technique for secure routing. It used an independent approach with suitable mathematical which was
assumed to be computationally secured. Key distribution system was being applied on a secure policy based
routing. It was limited to conversion of text file.
Ismail .I.A et al. [12] worked on how to repair the hill cipher. This technique adjusts the encryption key to form
a different key for each block encryption. This algorithm provides a method for adjusting the encryption key,
thereby significantly increasing its resistance to various attacks such as a known plaintext attack and statistical
attack. The proposed algorithm called HillMRIV cipher.
Yogesh Karandikar et al. [13] proposed on effective key management approach for differential access control in
dynamic environment. In group communication each user accesses multiple resources and multiple users can
access each resource. Each resource encryption key needs to be distributed to all subscribers of the resource and
each subscriber must get the entire key. So they developed a new approach of keys management to enforce
differential access control in highly dynamic environments for secure group communication framework.
Yanchao Zhang et al. [14] worked on Location-Based Compromise-Tolerant Security Mechanisms for Wireless
Sensor Networks. They worked on the notion of location-based keys by binding private keys of individual nodes
to both their IDs and geographic locations. They developed LBK-based neighbourhood authentication scheme to
localize the impact of compromised nodes to their vicinity.
N. R. Potlapally et al. [15] worked on energy consumption characteristics of cryptographic algorithms and
security protocols. They present a comprehensive analysis of the energy requirements of a wide range of
cryptographic algorithms that form the building blocks of security mechanisms such as security protocols. They
also discuss various opportunities for realizing energy efficient implementations of security protocols.
Darpan Anand et al. [16] explored identity based cryptography techniques and applications. They reviewed the
identity based encryption applications in the field of various networks as ad-hoc networks. The scheme also
used in mobile networks and other wireless networks. They also discussed that under what parameters identity
based cryptography was used with its benefits and limitations. The main limitation was that the available
methods were restricted to fixed output block, which was a trace for crackers.
Septimiu Fabian Mare et al. [17] worked on secret data communication system using steganography, AES and
RSA. They show new secret data communication system that employs the use of two cryptographic algorithms
RSA and AES together with steganography. The joining of these three techniques builds a robust steganography
based communication system capable of withstanding multiple types of attacks. The key used for the data
encryption uses a combination between a random generated sequence and a hash function.
Kundankumar Rameshwar Saraf et. al. [18] wrote a paper “Text and Image Encryption Decryption Using
Advanced Encryption Standard”. In this paper they described that images have large data size and also has real
time constrain problem hence similar method cannot be used to protect images as well as text from unauthorized
access. However with few variations in method AES can be used to protect image as well as text. They had
implemented encryption and decryption for text and image using AES.
