International Journal of Electronics Communication and Computer Technology (IJECCT) Volume 3 Issue 2 (March 2013) ISSN:2249-7838 IJECCT | www.ijecct.org 398 Optimal Cryptographic Technique to increase the Data Security K Laxmi Narayan Assistant Professor, Department of ECE, Kodaikanal Institute of Technology Machur, Kodaikanal, India S Jafar Ali Ibrahim Assistant Professor, Dept of IT Kodaikanal Institute of Technology Machur, Kodaikanal, India Abstract— There are many aspects to security ranging from secure commerce and payments to private communications and protecting passwords. One essential aspect for secure communications is that of secret key Cryptography. It is the automated method in which security goals are accomplished. It includes the process of encryption that converts plain-text into cipher-text. The process of decryption reconverts the cipher-text into plain-text. Secure communication is the prime requirement of every organization. To achieve this, one can use many techniques or algorithms available for Cryptography. In this context, we analyze and implement extremely protected cryptography scheme using the properties of quaternion which is the extension of the complex numbers and Farey fractions, Farey sequence of order n is the sequence of completely reduced fractions between 0 and 1. The proposed techniques in this paper can help in increasing the accurateness and wholeness of network topology discovery and can control existing protocol and hardware features, and also can be implemented easily. Keywords: Cryptography; Quaternion; Number theory; Farey fractions; Computer network Security; resource management. I. INTRODUCTION Security attacks against network are increasing significantly with time. Our communication media should also be secure and confidential. For this purpose, these three suggestions arrive in every one’s mind: (i) one can transmit the message secretly, so that it can be saved from hackers, (ii) the sender ensures that the message arrives to the desired destination, and (iii) the receiver ensures that the received message is in its original form and coming from the right sender. For this, one can use two techniques: (i) one can use invisible ink for writing the message or can send the message through the confidential person, and (ii) one can use a scientific approach called “Cryptography”. Cryptography is the technique used to avoid unauthorized access of data. For example, data can be encrypted using a cryptographic algorithm in conjunction with the key management. It will be transmitted in an encrypted state, and later decrypted by the intended party. If a third party intercepts the encrypted data, it will be difficult to decipher. The security of modern cryptosystems is not based on the secrecy of the algorithm, but on the secrecy of a relatively small amount of information, called a secret key. The fundamental and classical task of cryptography is to provide confidentiality by encryption methods [1]. Cryptography is used in applications present in technologically advanced societies; examples include the security of ATM cards, computer passwords, and electronic commerce, which all depend on cryptography. Cryptanalysis is the study used to describe the methods of code-breaking or cracking the code without using the security information, usually used by hackers. II. OBJECTIVE Cryptography is used to achieve the following goals: A. Confidentiality: Protection against unauthorized disclosure of information. Confidentiality may be applied to whole messages, parts of messages, and even existence of messages. Confidentiality is the protection of transmitted data from passive attacks. B. Authentication: The authentication service is concerned with assuring that a communication is authentic. It is the corroboration of the claimed source of a message. Authentication is of two types: (i) Peer entity, and (ii) Data origin C. Data integrity: The integrity can apply to a stream of messages, a single message, or selected fields within a message. It assures that messages are received as sent, with no duplication, insertion, modification, reordering, or replays. The destruction of data is also covered under this service. D. Access Control: It is the ability to limit and control the access to host systems and applications via communications links. To achieve this, each entity trying to gain access must first be identified, or authenticated, so that access rights can be tailored to the individual. E. Nonrepudiation: Nonrepudiation prevents either sender or receiver from denying a transmitted message. When a message is sent, the