Iskanje po katalogu digitalne knjižnice

Opis: While vehicle ad-hoc networks (VANETs) have many advantages, they also present privacy and security concerns. Certificate management issue has been seen in traditional public key infrastructure based privacy preserving authentication schemes while key escrow problem exists in identity based privacy preserving authentication techniques. Also existing cryptographic techniques rely heavily on assumptions about tamper-proof equipment to ensure their security. A proposal has been made for a certificateless aggregate signature system for VANETs addressing these issue and was proved provably unforgeable against collusion attack. However we found that the proposed technique was insecure and cannot withstand collusion assault. Therefore, this paper presents an improved and secure certificateless aggregate signature technique for VANETs. We also illustrate the security & performance evaluation of our presented technique and based upon the hardness assumption of the elliptic curve discrete logarithm problem we have shown that the technique is safe against existential forgery on adaptive chosen message attack in the random oracle model. Also the presented technique has better efficiency compared to some recent existing authentication techniques.
Ključne besede: aggregate signature, certificateless public key cryptography, elliptic curve cryptosystem, vehicular ad hoc networks
Objavljeno v DKUM: 13.03.2025; Ogledov: 0; Prenosov: 4
Celotno besedilo (888,32 KB)

Opis: Cryptography first appeared approximately four thousand years ago; it has developed and improved throughout history. Cryptography has an important role in the modern world. Cryptography has been a part of our lives for nearly four thousand years; nevertheless, the first book on cryptography did not appear until 1499, when John Tritheim published a collection of codes used in some European courts. Today, cryptography affects us in many seen and unseen forms and shapes. Therefore, I am not surprised to see that it is commonplace in fiction. The purpose of this thesis is not to study the light summer reading that has lately filled the bookshelves, but to systematically research the complexity of cryptography in different literary genres. In The Complexity of Cryptography in Literature, I analyze cryptography in English literature throughout the past two centuries. My thesis is, for many reasons, written in English; the study of English and American Literature, an English speaking mentor and researching literature written in English. Using analysis and synthesis I study two secondary theoretical sources, Codes and Ciphers – A History of Cryptography written by Alexander D'Agapeyeff and Codes, Ciphers and Secret Writing written by Martin Gardner. At the same time I introduce the appropriate terminology which is necessary for further understanding. The thesis summarizes and presents the history of cryptography. The latter is researched using the method of analysis and synthesis in The Code Book by Simon Sing and The Code-Breakers by David Kahn. Using the basic methods and history of cryptography, I will show that many methods of cryptography are described in literature; these are closely related to cryptography’s historical development. Furthermore, I propose that these methods are used in a wide spectra of literary genres; at the same time I will show that mostly simple or simplified methods of cryptography are used in literature; otherwise, they would not be accessible to the average reader. The thesis analyzes the complexity of cryptography in six different works of literature with reference to standard mathematical models of cryptography. I analyze the above mentioned works of literature, and using classification and mathematical methods, I process and present the appearance of cryptography in individual works (the methods and their correctness); then, using historical and comparative methods, I research the relationship between cryptographic methods used in literature and actual historical use of cryptography. Further on, I use various methods (the mathematical method, the method of analysis and synthesis, the method of interpretation, and the descriptive method) to present the complexity of cryptographic methods in literature.
Ključne besede: cryptography, code, cipher, complexity, fiction
Objavljeno v DKUM: 26.08.2016; Ogledov: 2304; Prenosov: 170
Celotno besedilo (2,49 MB)