Efficient Authenticated Encryption Schemes with Public Verifiability

An authenticated encryption scheme allows messages to be encrypted and authenticated simultaneously. In 2003, Ma and Chen proposed such a scheme with public verifiability. That is, in their scheme the receiver can efficiently prove to a third party that a message is indeed originated from a specific sender. In this paper, we first identify two security weaknesses in the Ma-Chen authenticated encryption scheme. Then, based on the Schnorr signature, we proposed an efficient and secure improved scheme such that all the desired security requirements are satisfied.Comment: Early version appears in the Proc. of The 60th IEEE Vehicular Technology Conference (VTC 2004-Fall) - Wireless Technologies for Global Security. IEEE, 200

Password Cracking and Countermeasures in Computer Security: A Survey

With the rapid development of internet technologies, social networks, and other related areas, user authentication becomes more and more important to protect the data of the users. Password authentication is one of the widely used methods to achieve authentication for legal users and defense against intruders. There have been many password cracking methods developed during the past years, and people have been designing the countermeasures against password cracking all the time. However, we find that the survey work on the password cracking research has not been done very much. This paper is mainly to give a brief review of the password cracking methods, import technologies of password cracking, and the countermeasures against password cracking that are usually designed at two stages including the password design stage (e.g. user education, dynamic password, use of tokens, computer generations) and after the design (e.g. reactive password checking, proactive password checking, password encryption, access control). The main objective of this work is offering the abecedarian IT security professionals and the common audiences with some knowledge about the computer security and password cracking, and promoting the development of this area.Comment: add copyright to the tables to the original authors, add acknowledgement to helpe

Image encryption system based on a nonlinear joint transform correlator for the simultaneous authentication of two users

We propose a new encryption system based on a nonlinear joint transform correlator (JTC) using the information of two biometrics (one digital fingerprint for each user) as security keys of the encryption system. In order to perform the decryption and authentication in a proper way, it is necessary to have the two digital fingerprints from the respective users whose simultaneous authentication is pursued. The proposed security system is developed in the Fourier domain. The nonlinearity of the JTC along with the five security keys given by the three random phase masks and the two digital fingerprints of the two users allow an increase of the system security against brute force and plaintext attacks. The feasibility and validity of this proposal is demonstrated using digital fingerprints as biometrics in numerical experiments.Peer ReviewedPostprint (published version

Quantifying Shannon's Work Function for Cryptanalytic Attacks

Attacks on cryptographic systems are limited by the available computational resources. A theoretical understanding of these resource limitations is needed to evaluate the security of cryptographic primitives and procedures. This study uses an Attacker versus Environment game formalism based on computability logic to quantify Shannon's work function and evaluate resource use in cryptanalysis. A simple cost function is defined which allows to quantify a wide range of theoretical and real computational resources. With this approach the use of custom hardware, e.g., FPGA boards, in cryptanalysis can be analyzed. Applied to real cryptanalytic problems, it raises, for instance, the expectation that the computer time needed to break some simple 90 bit strong cryptographic primitives might theoretically be less than two years.Comment: 19 page

Review on DNA Cryptography

Cryptography is the science that secures data and communication over the network by applying mathematics and logic to design strong encryption methods. In the modern era of e-business and e-commerce the protection of confidentiality, integrity and availability (CIA triad) of stored information as well as of transmitted data is very crucial. DNA molecules, having the capacity to store, process and transmit information, inspires the idea of DNA cryptography. This combination of the chemical characteristics of biological DNA sequences and classical cryptography ensures the non-vulnerable transmission of data. In this paper we have reviewed the present state of art of DNA cryptography.Comment: 31 pages, 12 figures, 6 table

Pendekatan konstruktif dalam inovasi pengajaran dan pembelajaran Bahasa Melayu di Kolej Vokasional

Pendekatan konstruktif adalah pendekatan pengajaran dan pembelajaran yang berpusatkan pelajar manakala inovasi pengajaran pula dikaitkan dengan kaedah pengajaran yang terbaru demi mengukuhkan pemahaman pelajar. Pembelajaran berasaskan pendekatan konstruktif merupakan elemen yang penting dan perlu difahami oleh guru-guru bagi memantapkan proses pengajaran dan pembelajaran sesuai dengan peredaran masa dan menjayakan proses tranformasi pendidikan negara. Objektif kajian ini dijalankan untuk mengenal pasti pemahaman guru-guru bahasa Melayu berkaitan inovasi, mengenal pasti perbezaan yang wujud antara guru lelaki dan guru perempuan dalam mengamalkan inovasi, pengkaji juga melihat adakah wujud perbezaan antara guru baru dan guru yang sudah berpengalaman dalam aspek mengaplikasikan inovasi serta mengenal pasti kekangan-kekangan yang dialami oleh para guru untuk mengaplikasikan inovasi di sekolah. Seramai 63 orang guru bahasa Melayu dari lapan buah kolej vokasional telah dipilih sebagai responden dalam kajian ini. Data dianalisis menggunakan perisian Winsteps 3.69.1.11 dengan pendekatan Model Pengukuran Rasch. Hasil analisis menunjukkan bahawa guru�guru bahasa Melayu memahami kepentingan inovasi dalam pengajaran dan pembelajaran. Hasil kajian juga menunjukkan guru-guru perempuan lebih banyak menerapkan unsur inovasi dalam pengajaran berbanding guru lelaki. Walaupun begitu, aspek pengalaman tidak menunjukkan perbezaan dari segi pengamalan inovasi sama ada guru baru ataupun guru yang sudah berpengalaman. Pengkaji juga mengenal pasti beberapa kekangan yang dialami oleh guru-guru untuk mengamalkan inovasi ini. Sebagai langkah untuk menangani masalah berkenaan, beberapa cadangan telah dikemukakan oleh pengkaji bagi memastikan guru-guru dapat merealisasikan proses pengajaran berkesan dengan penerapan inovasi mengikut model pendekatan konstruktif. Pengkaji berharap, kajian ini dapat dijadikan sebagai satu panduan kepada pelaksana kurikulum bagi memastikan budaya inovasi sentiasa menjadi amalan dalam kalangan guru demi mengangkat profesionalisme guru di Malaysia