Conventional key distribution methods using on Pay-TV system emphasize on the method¡¦s refinement in order to reduce the quantity of the keys distributed over network. This paper brings up the manner using digital watermarking technique to hide the cryptographic keys into routine encrypted video file without any increment of video file size for the economy of network bandwidth. The experimental results show that the proposed method works well in image quality and economical key distribution.

Most process of lease is done manually in the past. Since the networks were used extensively and systems of Point of Sales risen quickly, the efficiency of administration of payment flow had been obviously promoted. What are mostly encrypted are information of payment flow, but what we encrypt is the information of leased products this time. We apply encryption technique to the lease system, and access information via RS-232 devices, such as SmartCard Reader and EM Reader. After processing of system and encryption, the system will transfer the processed data to the server. In this paper, we take Kaohsiung C-Bike Lease System for case study, our discussion will focus on network packet, data encryption, and real-time monitoring. We will also introduce critical features and mechanisms of the lease system and address some issues we encountered. This system encrypts data via Advanced Encryption Standard, sends out data packets via TCP/IP, and monitors leased bikes via databases and framework of multi-thread.

In this thesis, we used a encryption mechanism based on AES(Advenced Encryption Standard). Except for this mechanism, we also combine RS-232 Serial Communication Control, Smartcard and EM card which originally used in the Entrance Guard System to implement a new system. Eventually, this new system applies to a certain rental system practically. We also introduce some functions of this rental system based on the encryption mechanism, station initialization, bike rental, bike allocation and bike rental for credit card for example. In addition, we will describe what problems we met and the solutions we introduced to the problems finally.

<p>I detta arbete undersöks hur kryptering påverkar prestandan hos en XML-databas. Detta görs med hjälp av ett inom litteraturen populärt dataset, XMark. Kryptering genomförs med hjälp av standarden XML Encryption. Okrypterade dataset jämförs med krypterade dataset genom att ställa Xpath-frågor och mäta tiden för dessa frågeställningar. Resultaten presenteras i tabeller och grafer och analyseras utifrån ett prestandaperspektiv. Även framtida utökning av testerna föreslås som framtida arbete.</p>

<p>Radio frequency identification, RFID is a technology that is used in many fields including locks. The unlimited access to the reader and the transponder has resulted in severe security weaknesses and made it possible to apply different attacks. To classify door locks as secure they must at least fulfil two main criteria: the first is the use of a challenge-response authentication protocol and the second is to deploy sophisticated and secure algorithms.</p><p>MiFare classic and KeeLoq are two widely applied technologies that are still in use in many security critical applications and are considered to be secure but which have been broken by cryptanalysis and with modest efforts and cost.</p><p>How secure a certain solution is depends on how expensive it is to buy the equipment that can break the system and reveal the secret key and how secure a lock should be depends on the value of what it is protecting.</p><p>The dropping price of powerful computers and the availability of security related information on the web will lead to an increase of the number of attacks on different systems.</p><p>By the time this thesis is published those locks evaluated are not secure enough, to overcome the security shortage some improvements have to be made such as: the use of sophisticated algorithms, the use of longer key of at least 128-bit, the use of non-deterministic random number generators and the use of pure hardware solutions both in the receiver and the transmitter to reduce leakage.</p>

<p>Stream ciphers are counted as an important part of symmetric encryption method. Their basic idea comes from One-Time-Pad cipher using XOR operator on the plain text and the key to generate the cipher. The present work brings a new idea in symmetric encryption method, which inherits stream key generation idea from synchronous stream cipher and uses division instead of xoring. The Usage of division to combine the plain text with stream key gives numerous abilities to this method that the most important one is using random factors to produce the ciphers.</p>

Thesis (Ph. D.)--State University of New York at Binghamton, Electrical Engineering Department, 2001. / Includes bibliographical references (leaves 50-52).

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 129-135). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: computer arithmetic; elliptic curves; cryptography. Includes bibliographical references (p. 299-305).

Thesis (M.Eng.)--Memorial University of Newfoundland, 2000. / Bibliography: p. 101-108.