Implementation of cryptographic algorithms and protocols

The purpose of the project is to provide a practical survey of both the principles and practice of cryptography. Cryptography has become an essential tool in transmission of information. Cryptography is the central part of several fields: information security and related issues, particularly, authentication, and access control. Cryptography encompasses a large number of algorithms which are used in building secure applications

Re-engineering the Enigma cipher.

The design of this thesis is to re-engineer the Enigma cipher to make it a viable, secure cipher for use on current computers. The goal is to create a cipher based on an antiquated mechanical cryptography device, the Enigma Machine, in software and improve upon it. The basic principle that is being expounded upon here is that while the Enigma cipher\u27s security was originally very dependent on security through obscurity, this needs to be secure on its own. Also, this must be a viable solution for the encryption of data based on modern standards. The Enigma Phoenix, the name for this new cipher, will use Galois functions and other modern improvements to add an extra level of security to it and to make it the viable solution that is desired

Web-based application for cryptographic protocols visualization

Práce se zabývá vytvořením interaktivní webové aplikace pro substituční šifry a jejich interaktivní kryptoanalýzu. V práci je implementováno šest šifer a zástupci monoalfabetických šifer jsou Caesarova šifra, Atbaš a substituce s klíčovým slovem. Dále zástupci polyalfabetických šifer jsou Vigenrova šifra, Kryptos a Vernamova šifra. Pro interaktivní analýzu je použita frekvenční analýza, index koincidence a n-gramová statistika jako fitness funkce. Výsledek byl dosažen za pomoci HTML5, CSS a skriptovacího jazyka ReactJS což je JavaScriptová knihovna s možností typové kontroly proměnných.The thesis deals with the creation of an interactive web application for substitution ciphers and their interactive cryptanalysis. Six ciphers are implemented in the work. Representatives of monoalphabetic ciphers are Caesar’s cipher, Atbash, and Keyword cipher and representatives of polyalphabetic ciphers are Vigenre cipher, Kryptos and Vernam cipher. Frequency analysis, index of coincidence and n-gram statistics as a fitness function are used for interactive cryptanalysis. The result is achieved by using HTML5, CSS and ReactJS scripting language which is a JavaScript library with the ability of variable type-check.

Modified honey encryption scheme for encoding natural language message

Conventional encryption schemes are susceptible to brute-force attacks. This is because bytes encode utf8 (or ASCII) characters. Consequently, an adversary that intercepts a ciphertext and tries to decrypt the message by brute-forcing with an incorrect key can filter out some of the combinations of the decrypted message by observing that some of the sequences are a combination of characters which are distributed non-uniformly and form no plausible meaning. Honey encryption (HE) scheme was proposed to curtail this vulnerability of conventional encryption by producing ciphertexts yielding valid-looking, uniformly distributed but fake plaintexts upon decryption with incorrect keys. However, the scheme works for only passwords and PINS. Its adaptation to support encoding natural language messages (e-mails, human-generated documents) has remained an open problem. Existing proposals to extend the scheme to support encoding natural language messages reveals fragments of the plaintext in the ciphertext, hence, its susceptibility to chosen ciphertext attacks (CCA). In this paper, we modify the HE schemes to support the encoding of natural language messages using Natural Language Processing techniques. Our main contribution was creating a structure that allowed a message to be encoded entirely in binary. As a result of this strategy, most binary string produces syntactically correct messages which will be generated to deceive an attacker who attempts to decrypt a ciphertext using incorrect keys. We evaluate the security of our proposed scheme

Transcriptase–Light: A Polymorphic Virus Construction Kit

Many websites use JavaScript to display dynamic and interactive content. Hence, attackers are developing JavaScript–based malware. In this paper, we focus on Transcriptase JavaScript malware. The high–level and dynamic nature of the JavaScript language helps malware writers to create polymorphic and metamorphic malware using obfuscation techniques. These types of malware change their internal structure on each infection, making them difficult to detect with traditional methods. These types of malware can be detected using machine learning methods. This project creates Transcriptase–Light, a new polymorphic construction kit. We perform an experiment with the Transcriptase–Light against a hidden Markov model. Our experiment shows that the HMM based detector failed in detecting Transcriptase–Light. After observing the results, we try to detect malware using the decryption part of Transcriptase–Light. To avoid detection, we generate the polymorphic version of the decryption part

Synchronization of multi-carrier CDMA signals and security on internet.

by Yooh Ji Heng.Thesis (M.Phil.)--Chinese University of Hong Kong, 1996.Includes bibliographical references (leaves 119-128).Appendix in Chinese.Chapter I --- Synchronization of Multi-carrier CDMA Signals --- p.1Chapter 1 --- Introduction --- p.2Chapter 1.1 --- Spread Spectrum CDMA --- p.4Chapter 1.1.1 --- Direct Sequence/SS-CDMA --- p.5Chapter 1.1.2 --- Frequency Hopping/SS-CDMA --- p.5Chapter 1.1.3 --- Pseudo-noise Sequence --- p.6Chapter 1.2 --- Synchronization for CDMA signal --- p.7Chapter 1.2.1 --- Acquisition of PN Sequence --- p.7Chapter 1.2.2 --- Phase Locked Loop --- p.8Chapter 2 --- Multi-carrier CDMA --- p.10Chapter 2.1 --- System Model --- p.11Chapter 2.2 --- Crest Factor --- p.12Chapter 2.3 --- Shapiro-Rudin Sequence --- p.14Chapter 3 --- Synchronization and Detection by Line-Fitting --- p.16Chapter 3.1 --- Unmodulated Signals --- p.16Chapter 3.2 --- Estimating the Time Shift by Line-Fitting --- p.19Chapter 3.3 --- Modulated Signals --- p.22Chapter 4 --- Matched Filter --- p.23Chapter 5 --- Performance and Conclusion --- p.27Chapter 5.1 --- Line Fitting Algorithm --- p.27Chapter 5.2 --- Matched Filter --- p.28Chapter 5.3 --- Conclusion --- p.30Chapter II --- Security on Internet --- p.31Chapter 6 --- Introduction --- p.32Chapter 6.1 --- Introduction to Cryptography --- p.32Chapter 6.1.1 --- Classical Cryptography --- p.33Chapter 6.1.2 --- Cryptanalysis --- p.35Chapter 6.2 --- Introduction to Internet Security --- p.35Chapter 6.2.1 --- The Origin of Internet --- p.35Chapter 6.2.2 --- Internet Security --- p.36Chapter 6.2.3 --- Internet Commerce --- p.37Chapter 7 --- Elementary Number Theory --- p.39Chapter 7.1 --- Finite Field Theory --- p.39Chapter 7.1.1 --- Euclidean Algorithm --- p.40Chapter 7.1.2 --- Chinese Remainder Theorem --- p.40Chapter 7.1.3 --- Modular Exponentiation --- p.41Chapter 7.2 --- One-way Hashing Function --- p.42Chapter 7.2.1 --- MD2 --- p.43Chapter 7.2.2 --- MD5 --- p.43Chapter 7.3 --- Prime Number --- p.44Chapter 7.3.1 --- Listing of Prime Number --- p.45Chapter 7.3.2 --- Primality Testing --- p.45Chapter 7.4 --- Random/Pseudo-Random Number --- p.47Chapter 7.4.1 --- Examples of Random Number Generator --- p.49Chapter 8 --- Private Key and Public Key Cryptography --- p.51Chapter 8.1 --- Block Ciphers --- p.51Chapter 8.1.1 --- Data Encryption Standard (DES) --- p.52Chapter 8.1.2 --- International Data Encryption Algorithm (IDEA) --- p.54Chapter 8.1.3 --- RC5 --- p.55Chapter 8.2 --- Stream Ciphers --- p.56Chapter 8.2.1 --- RC2 and RC4 --- p.57Chapter 8.3 --- Public Key Cryptosystem --- p.58Chapter 8.3.1 --- Diffie-Hellman --- p.60Chapter 8.3.2 --- Knapsack Algorithm --- p.60Chapter 8.3.3 --- RSA --- p.62Chapter 8.3.4 --- Elliptic Curve Cryptosystem --- p.63Chapter 8.3.5 --- Public Key vs. Private Key Cryptosystem --- p.64Chapter 8.4 --- Digital Signature --- p.65Chapter 8.4.1 --- ElGamal Signature Scheme --- p.66Chapter 8.4.2 --- Digital Signature Standard (DSS) --- p.67Chapter 8.5 --- Cryptanalysis to Current Cryptosystems --- p.68Chapter 8.5.1 --- Differential Cryptanalysis --- p.68Chapter 8.5.2 --- An Attack to RC4 in Netscapel.l --- p.69Chapter 8.5.3 --- "An Timing Attack to Diffie-Hellman, RSA" --- p.71Chapter 9 --- Network Security and Electronic Commerce --- p.73Chapter 9.1 --- Network Security --- p.73Chapter 9.1.1 --- Password --- p.73Chapter 9.1.2 --- Network Firewalls --- p.76Chapter 9.2 --- Implementation for Network Security --- p.79Chapter 9.2.1 --- Kerberos --- p.79Chapter 9.2.2 --- Privacy-Enhanced Mail (PEM) --- p.80Chapter 9.2.3 --- Pretty Good Privacy (PGP) --- p.82Chapter 9.3 --- Internet Commerce --- p.83Chapter 9.3.1 --- Electronic Cash --- p.85Chapter 9.4 --- Internet Browsers --- p.87Chapter 9.4.1 --- Secure NCSA Mosaic --- p.87Chapter 9.4.2 --- Netscape Navigator --- p.89Chapter 9.4.3 --- SunSoft HotJava --- p.91Chapter 10 --- Examples of Electronic Commerce System --- p.94Chapter 10.1 --- CyberCash --- p.95Chapter 10.2 --- DigiCash --- p.97Chapter 10.3 --- The Financial Services Technology Consortium --- p.98Chapter 10.3.1 --- Electronic Check Project --- p.99Chapter 10.3.2 --- Electronic Commerce Project --- p.101Chapter 10.4 --- FirstVirtual --- p.103Chapter 10.5 --- Mondex --- p.104Chapter 10.6 --- NetBill --- p.106Chapter 10.7 --- NetCash --- p.108Chapter 10.8 --- NetCheque --- p.111Chapter 11 --- Conclusion --- p.113Chapter A --- An Essay on Chinese Remainder Theorem and RSA --- p.115Bibliography --- p.11

The design of a secure data communication system

The recent results of using a new type of chosen-plaintext attack, which is called differential cryptanalysis, makes most published conventional secret-key block cipher systems vulnerable. The need for a new conventional cipher which resists all known attacks was the main inspiration of this work. The design of a secret-key block cipher algorithm called DCU-Cipher, that resists all known cryptanalysis methods is proposed in this dissertation. The proposed method is workable for either 64-bit plaintext/64-bit ciphertext blocks, or 128-bit plaintext/128-bit ciphertext blocks. The secret key in both styles is 128-bit long. This method has only four rounds and the main transformation function in this cipher algorithm is based on four mixed operations. The proposed method is suitable for both hardware and software implementation. It is also suitable for cryptographic hash function implementations. Two techniques for file and/or data communication encryption are also proposed here. These modes are modified versions of the Cipher-Block Chaining mode, by which the threat of the known-plaintext differential cyptanalytical attack is averted. An intensive investigation of the best known Identity-based key exchange schemes is also presented. The idea behind using such protocols, is providing an authenticated secret-key by using the users identification tockens. These kind of protocols appeared recently and are not standardized as yet. None of these protocols have been compared with previous proposals. Therefore one can not realize the efficiency and the advantages of a new proposed protocol without comparing it with other existing schemes of the same type. The aim of this investigation is to clarify the advantages and the disadvantages of each of the best known schemes and compare these schemes from the complixity and the speed viewpoint

Computational Thinking across the Curriculum: A Conceptual Framework

We describe a framework for implementing computational thinking in a broad variety of general education courses. The framework is designed to be used by faculty without formal training in information technology in order to understand and integrate computational thinking into their own general education courses. The framework includes examples of computational thinking in a variety of general education courses, as well as sample in-class activities, assignments, and other assessments for the courses. The examples in the different courses are related and differentiated using categories taken from Peter Denning’s Great Principles of Computing, so that similar types of computational thinking appearing in different contexts are brought together. This aids understanding of the computational thinking found in the courses and provides a template for future work on new course materials

Using Offline Activities to Enhance Online Cybersecurity Education

Since the beginning of the 21st century, the United States has experienced the impact of a technological revolution. One effect of this technological revolution is the creation of entirely new careers related to the field of technology, including cybersecurity. Continued growth in the cybersecurity industry means a greater number of jobs will be created, adding to the existing number of jobs that are challenging an under-educated and under-trained workforce. The goal of this thesis is to increase the effectiveness of cybersecurity education. This thesis studies whether an online course in cybersecurity can be enhanced by offline, in-person activities that mirror traditional classroom methods. To validate the research, two groups of high school students participated in an online course with only one group participating in offline activities. The results showed that the group that participated in both the online and offline portions of the course had a higher percentage of student retention, a more positive mindset towards cybersecurity, and an improved performance in the course