Routine of Encryption in Cognitive Radio Network

Today data transmission is very important through different channels. Need of network security comes to secure data transformation from one network to another network. As the complexity of the systems and the networks increases, weakness expands and the task of securing the networks is becomes more convoluted. Duty of securing is done by Cryptography techniques. A colossal amount of data is exchanged over public networks like the internet due to immense accommodation. This includes personal details and confidential information. It is important to prevent the data from falling into the wrong hands. So, due to this factor we use cryptography. Encryption and decryption are the basic terms that are used in cryptography. There are few algorithms which used including, AES (Advanced Encryption Standard), DES (Data Encryption Standard), 3DES (Triple Data Encryption Standard) and BLOWFISH. The main contribution of this paper is to provide an algorithm that is useful for data transformation in cognitive radio networks. In this research, we have drawn a new symmetric key technique that is for the usage of cryptography which is helpful to make the data saved from others.


INTRODUCTION
T echnology now-a-days is common in our surroundings. With the passage of time, the transformation of data is increasing day by day and maintaining an old data in a system has gradually increases. Security is an important factor in transmission and saving the data. One important and essential aspect of communications is cryptography. Cryptography is the study of hiding information by converting the sensitive information into an unintelligible text using a suitable encryption technique so that it cannot be understood by any unintended individual, and then converting it back to its original form for the intended receiver using some decryption technique [1].
The cryptography has been used since ancient Roman and Egyptian empires. "Caesar Cipher" invented by

Routine of Encryption in Cognitive Radio Network
Julius Caesar is one such example. Now, the cryptography has been digitalized. Computer algorithms have modernized the art of cryptography. Cryptography has become an essential tool in protecting the sensitive information from unauthorized access and to provide information security. This technique has discovered its uses in defence and also in business field. Companies and firms use cryptography techniques to protect their data and information from their adversaries. It is also used to protect individual data and has extensive application in our daily lives [2].
Now-a-days there are four basic objectives of cryptography as mentioned in [3]. Confidentiality, Integrity, Non-Repudiation and Authentication.
Sometimes cryptography is referred to as encryption. The basic part of encryption is to provide an irregular scrambled key and concealing the first information by making key and encode this with key and spare from gatecrasher.
Encryption part is useful for securing the electronic transmission over unprotected systems. Fig. 1 describes the encryption, decryption process. By using some specific algorithm between 'plaintext and key' the cipher text is obtained, and this cipher text is transferred to the receiver. To get plain text again on the receiving end, some specific operation are performed between cipher text and key. This is known as decryption process.
A CR (Cognitive Radio) is a system or radio that senses and make us aware of its operational environment and can dynamically and autonomously adjust its radio operating parameters accordingly [4][5].The CR technology works on the principle of dynamic spectrum access where secondary user utilizes spectrum hole [6][7]. The objectives of CR networks are to determine the spectrum holes, select the best spectrum opportunities to meet the user communication requirements and avoid from any harmful interference for a primary user.
Transmission has its own importance in this network.
This study explores the new technique of encryption and data transmission in network.
The rest of the paper is organized as follows: Section 2 briefly describes the Cryptography types and some popular algorithms that being used in the recent days.
Section 3 outlines some issues found in old algorithms.
Our proposed, new technique is presented in Section 4.
Section 5 detailes implementation and Section 6 provides the performance evaluation of the proposed algorithm.
The conclusion is included in Section 7.

CRYPTOGRAPHY TYPES
Basically Encryption has three types [8]  Symmetric encryption  Asymmetric Encryption  Hashing

Symmetric Encryption
A sort of encryption that has just single key is often known as symmetric encryption [4]. It is one of the most widely used method of cryptography. There are different points of interest in this approach. Execution is decently high. This encryption technique is resonably secure (Fig. 2).

Asymmetric Encryption
Asymmetric encryption [9] utilizes two distinctive keys for encryption and decoding. The private key can just decode the encoded message [10]. No key, other than private key can be utilized for unscrambling (Fig. 3).

Hashing
Hash function is the one-way encryption method.
Moreover, no key is required for encryption and decryption.

Related Work and Popular Algorithms
Almost 4000 years ago Cryptography [11][12]

ISSUES FOUND IN ALGORITHMS
There are number of issues found in the existing algorithms:  Complex structure, and predictable due to short key length.

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The more complex structure of algorithm increases the time of execution. Therefore, the structure of algorithm must be simple to operate algorithm faster.

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The longer the length of the key, the higher the security. However, it affects the spped of execution of the algorithm [14].

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The overall performance of any algorithm depends upon the selection of mathematical and/or logical operations applied on plain text, key and cipher text.
In network security, there are two types of attacks. The former one is Active attack. Active attack tries to modify the systems resources and it affects operations performed on the system. The on the other hand, the passive attack is a try, which monitors the data transmission without affecting the operation performed in the system [20]. It is categorized as Eavesdropping, Collecting private data.

PROPOSED ALGORITHM
This section elaborates the security which we implemented for the plain text. Plain text and key are generated by using the ASCII (American Standard Code for Information Interchange) code. Proposed algorithm applies on plain text and obtained required cipher text, is more secure than prior algorithms. This algorithm is shown in Fig. 4.

IMPLEMENTATION OF DECRYPTION
(1) Read cipher text, user entered Sequence key.
Convert cipher text and key into binary value.
(2) Identify sequence key and remove. Two blocks obtained are Q' and R'

7.2
Testing Results by using HP1000

CONCLUSION
In this research paper, we have explored a new approach for accomplishing the secured information transmission in an upgraded way. The proposed approach is the symmetric key calculation and will read each plain text one by one and can convert it into cipher text by performing some operations. This proposed algorithm is efficient and easy to implement. From the result, it is proved that this approach is more reliable and faster than others.