AdilJamil Zaru. Int. Journal of Engineering Research and Application www.ijera.com ISSN : 2248-9622, Vol.08, Issue 02, ( Part -2)february 2018, pp.68-71 www.ijera.com DOI: 10.9790/9622-080206871 68 | Page General Summary of Cryptography AdilJamil Zaru 1 , Momeen Khan 2 Abstract Cryptographic mechanisms are an important security component of an operating system in securing the system itself and its communication paths. Indeed in many situations cryptography is the only tool that can solve a particular problem. It is the practice and study of techniques for secure communication in the presence of third parties. Modern cryptography is heavily based on mathematical theory, computer science practice and cryptographic algorithms. The algorithms are making in such a way it is difficult to break. Applications of cryptography include ATM cards, computer passwords, and electronic commerce. Keywords- foundations of cryptography, Plain Text, Cipher Text, Encryption,Security --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 10-02-2018 Date of acceptance: 28-02-2018 --------------------------------------------------------------------------------------------------------------------------------------- I. INTRODUCTION Can increased security provide comfort to paranoid people? Or can security provide some very basic protections that we are naïve to believe that we can’t need? During this time when the internet provides essential communication between tens of millions of people and is being increasingly used as a tool for commerce, security becomes a tremendously important issue to deal with it. One essential aspect for secure communications is that of cryptography. Cryptography has been used for many years. Its main goal is to make sensitive information unreadable to all but the intended recipient. There are so many methods that once were popular for hiding this sensitive data. However researchers and cryptanalysis succeeded to attack the secrecy of a number of these methods. The cryptographic keys must be established between the sender and the receiver either manually or using trusted third party key management. Figure-1 Classification of cryptographic algorithm The basic classification of cryptographic algorithms is shown in Figure 1. Many authors have compared these algorithms on the basis of time complexity and space complexity. This paper compares these algorithms on the basis of parameters like key length and management, security and limitations pertaining to each algorithm. II. PURPOSE OF CRYPTOGRAPHY Cryptography is the science of writing in secret code and is an ancient art. It is no surprise, then, that new forms of cryptography came soon after the widespread development of computer communications. In data and telecommunications, cryptography is necessary when communicating over any untrusted medium, which includes just about any network, particularly the Internet. Within the context of any application-to-application communication, there are some specific security requirements, including:  Authentication: The process of proving one's identity.  Privacy/confidentiality: Ensuring that no one can read the message except the intended receiver.  Integrity: Assuring the receiver that the received message has not been altered in any way from the original. Non-repudiation: A mechanism to prove that the sender really sent this message. Cryptography, then, not only protects data from theft or alteration, but can also be used for user authentication. III. TYPES OF CRYPTOGRAPHIC ALGORITHMS For purposes of this paper, cryptographic algorithms will be categorized based on the number of keys that are employed for encryption and decryption, and further defined by their application and use. In all cases the initial unencrypted data is RESEARCH ARTICLE OPEN ACCESS