Performance tests of cryptographic algorithms

Bakalářské práce se zabývá rozborem jednotlivých kryptografických algoritmů, které se využívají při zabezpečování komunikace. První část je věnována symetrickým kryptografickým algoritmům, asymetrickým kryptografickým algoritmům a hashovacím funkcím. Druhá část se zabývá bezpečností, stupni utajení a útoky, které se využívají při napadání kryptografických algoritmů a hashovacích funkcí. Třetí část se věnuje testování vybraného algoritmu RC4 a hashovací funkce MD5 za pomocí programu CrypTool. V závěrečné části jsou uvedeny a zhodnoceny výsledky testů algoritmu RC4 a hashovací funkce MD5.Bachelor's thesis deals with analysis of the various cryptographic algorithms that are used for securing communications. The first part is devoted to symmetrical cryptographic algorithms, asymmetric cryptographic algorithms and hashing functions. The second part deals with the security classification and attacks that are used to attack cryptographic algorithms and hash function. The third part deals with the selected testing algorithm RC4 and MD5 hashed function for using CrypTool. The final section provides an evaluation and test results of algorithm RC4 and MD5 hashing function.

ein Beitrag zur Didaktik der Kryptologie

We report on experiments on the time of factorization of semiprimes (i.e., products of two primes) using the systems ''Sage'' and ''CrypTool''. With some exceptions the time grows exponentially with the length of the semiprimes - as expected. Using the quadratic sieve implemented in CrypTool 2, we could factorize the number RSA-100, a 100-decimal-digits semiprime, on our laptop in less than eight and a half hours

Secure access to information panel

Bakalářská práce se zabývá zabezpečeným přístupem k informačnímu panelu, která řeší metody komunikace informačních panelů s řídící jednotkou. Jsou zde popsána komunikační rozhraní. Práce je zaměřena především na komunikační protokoly a metody zabezpečení přenosu zobrazovaných informací. Práce se zabývá protokolem Diffie-Hellman, který je podrobně rozebrán. Je zde vysvětlena podstata útoku „Man in the middle“ na protokol Diffie-Hellman. Způsob obrany proti útoku „Man in the middle“ použitím digitálního podpisu v protokolu Diffie-Hellman po nezabezpečeném komunikačním kanálu. V závěru je navrhnuta koncepce modulu pro zabezpečenou komunikaci mezi zobrazovacím panelem a řídícím terminálem. Podrobně jsou popsány tři navržené simulace v programu.My Thesis deals with secure access to the information panel, which deals with methods of communication of information panels with control unit. There are described the communication interface. The Thesis is focused mainly on communication protocols and security methods of transmission of information. The Thesis deals with the Diffie-Hellman Protocol, which is detailed discussed. There is explained the nature of the attack, the „Man in the middle“ on the Diffie-Hellman Protocol. A method of defense against attack by the „Man in the middle“ by using a digital signature in the Diffie-Hellman Protocol over an unsecured communication channel. In conclusion, the concept is designed for secure communications between the display panel and the control Terminal. There are described in detail the three proposed simulation in the programme.

15. GI-Fachtagung „Informatik und Schule“: Praxisband

“INFOS 2013” is the 15th event in a conference series organized by the GI special interest group IBS, which focuses on education in informatics (computer science) in schools. This volume contains experience reports and material accompanying most of the workshops which were part of conference

Praktična primena softverskih alata otvorenog koda u kriptografiji

Security of computer systems is becoming more important, because more users in more ways use more information in the computer world. With the development of information technologies and telecommunication systems and a greater diffusion in the geographical sense growing is also the possibility of misuse of data which are transferred through open and insecure communication paths which requires a more efficient protection. In the system of data transfer attackers can easily destroy data, modify them or the information can come into possession of unauthorized persons or organizations which can often have very heavy consequences. The problem is especially expressed in some organizations such as state administrations, banking, judicial, military, medical and other administrations. In this paper explained are basic terms related to crypts and algorithms which were used and which are used, as well as methods of data protection in computer networks based on cryptography in order to protect privacy inside a network of computers. Explained are symmetrical and asymmetrical cryptosystems and the technique of digital signature. Also, the subject of this paper is the presentation of the program CrypTool and CryptoWork flow, which belong to the most famous free ie. shareware software in the field of cryptography, with special emphasis on the possibility of applying different algorithms and comparative analysis of their work and are given concrete examples of their use.Sigurnost računarskih sistema oduvek je bitna, a danas postaje još važnija, jer sve više korisnika na sve više načina koristi sve više informacija u sadašnjem informatičkom svetu. Sa razvojem informacionih tehnologija i telekomunikacionih sistema i sve većom rasprostranjenošću ljudskog društva u geografskom smislu raste i mogućnost zloupotreba podataka koji se prenose otvorenim komunikacijskim putevima, što zahteva efikasniju zaštitu. U sistemu prenosa podataka napadači mogu lako da unište podatke, da ih modifikuju ili da informacije dođu u posed neovlašćenim osobama ili organizacijama, što može imati vrlo teške posledice. Problem je posebno izražen kod nekih organizacija kao što su državne administracije, pravosudne, vojne, medicinske, bankarske ali i druge. U ovom radu su objašnjeni osnovni pojmovi vezani za kriptovanje i algoritmi koji su se koristili i koji se koriste, kao i metode zaštite podataka u računarskim mrežama bazirane na kriptografiji kako bi se zaštitila takozvano sveto trojstvo sigurnosti CIA (od početnih slova engleskih reči: poverljivost - confidentiality, integritet - integrity, dostupnost - availability) unutar mreže računara. U radu su objašnjeni simetrični i asimetrični kriptosistemi i tehnika digitalnog potpisa. Takođe, predmet rada je predstavljanje programa CrypTool i CryptoWork flow, koji spadaju u najpoznatije slobodne, tj. shareware softvere u oblasti kriptografije, sa posebnim naglaskom na mogućnosti primene različitih algoritama, kao i komparativna analiza njihovog rada, a dati su i konkretni primeri njihovog korišćenja

Analisis Perbandingan antara Algoritma Rijndael dan Algoritma Twofish dalam Penyandian Teks

Kemudahan pengaksesan media komunikasi dengan memanfaatkan kemajuan teknologi informasi tentunya akan memberikan dampak bagi keamanan informasi atau pesan yang menggunakan media komunikasi tersebut. Penyandian terhadap file diperlukan untuk meminimalisasi file yang akan dikirim atau yang disimpan agar tidak diketahui, dimanipulasi atau diambil oleh pihak yang tidak bertanggungjawab, maka dibutuhkan metode yang dapat menjaga kerahasiaan suatu informasi yang salah satunya adalah kriptografi. Algoritma rijndael dan twofish sama-sama memiliki panjang kunci yang dapat digunakan, yaitu 128, 192 dan 256 bit. Algoritma rijndael memiliki putaran sebanyak 10 kali dengan panjang kunci 128 bit dan melakukan beberapa transformasi dalam proses enkripsi dan dekripsinya. Algoritma twofish menggunakan sejenis jaringan feistel, fungsi f, MDS matriks dan pseudo hadamard transform dengan putaran sebanyak 16 kali dengan panjang kunci 128 bit dalam proses enkripsi dan dekripsinya

Faculty Workshops for Teaching Information Assurance through Hands-On Exercises and Case Studies

Though many Information Assurance (IA) educators agree that hands-on exercises and case studies improve student learning, hands-on exercises and case studies are not widely adopted due to the time needed to develop them and integrate them into curriculum. Under the support of the National Science Foundation (NSF) Scholarship for Service program, we organized two faculty development workshops to disseminate effective hands-on exercises and case studies developed through multiple previous and ongoing grants. To develop faculty expertise in IA, the workshop covered a wide range of IA topics. This paper describes the hands-on exercises and case studies we disseminated through the workshops and reports our experiences of holding the faculty summer workshops. The evaluation results show that workshop participants demonstrated high levels of satisfaction with knowledge and skills gained in both the 2012 and 2013 workshops. Workshop participants also reported use of hands-on lab and case study materials in our follow-up survey and interviews. The workshops provided a valuable opportunity for IA educators to communicate and form collaborations in teaching and research in IA

Algorithm 959: VBF: A Library of C plus plus Classes for Vector Boolean Functions in Cryptography

VBF is a collection of C++ classes designed for analyzing vector Boolean functions (functions that map a Boolean vector to another Boolean vector) from a cryptographic perspective. This implementation uses the NTL library from Victor Shoup, adding new modules that call NTL functions and complement the existing ones, making it better suited to cryptography. The class representing a vector Boolean function can be initialized by several alternative types of data structures such as Truth Table, Trace Representation, and Algebraic Normal Form (ANF), among others. The most relevant cryptographic criteria for both block and stream ciphers as well as for hash functions can be evaluated with VBF: it obtains the nonlinearity, linearity distance, algebraic degree, linear structures, and frequency distribution of the absolute values of the Walsh Spectrum or the Autocorrelation Spectrum, among others. In addition, operations such as equality testing, composition, inversion, sum, direct sum, bricklayering (parallel application of vector Boolean functions as employed in Rijndael cipher), and adding coordinate functions of two vector Boolean functions are presented. Finally, three real applications of the library are described: the first one analyzes the KASUMI block cipher, the second one analyzes the Mini-AES cipher, and the third one finds Boolean functions with very high nonlinearity, a key property for robustness against linear attacks

Cryptography and implementation in Notes and Domino

Tato bakalářská práce se zabývá popisem kryptografie a infrastruktury veřejného klíče v Lotus Notes/Domino. Cílem je podat stručný přehled kryptografických technik včetně jejich implementace v Lotus Notes/Domino a navržení vhodných příkladů pro demonstraci a výuku kryptografických technik. Pro demonstraci vybraných algoritmů je použit volně šiřitelný výukový program CrypTool.This bachelor's thesis deals with description of cryptography and Public Key Infrastructure in Lotus Notes/Domino. The goal of this thesis is to give a brief overview of cryptographic techniques including their implementation in Lotus Notes/Domino and to propose an appropriate examples for demonstration and education in cryptographic techniques. In order to demonstrate selected algorithms an open-source e-learning software CrypTool is used.

Power quality measuring system

Tato práce se zabývá problematikou měření kvality elektrické energie. Budou rozebrány parametry, dle kterých se kvalita hodnotí, dále budou popsány systémy dálkového sběru dat a s nimi spojené technologie přenosu. V dnešní době by se také nemělo zapomínat na zabezpečení přenášených dat. Z tohoto důvodu budou také popsány a testovány nejrůznější druhy kryptografických algoritmů. Budou realizovány kryptografické algoritmy, pomocí kterých je možné zabezpečit datovou komunikaci ze sběrných míst dálkového měření. Kryptografické algoritmy budou realizovány nejprve v simulačním prostředí MATLAB a následně v jazyce C/C++. V poslední části práce je navržen a realizován simulační model sběrné sítě dálkového měření kvality elektrické energie.This thesis deals with the measurement of power quality. The evaluating quality parameters, data collection systems and transfer technologies will be discussed. The various type of cryptographic algorithms are also described. Cryptographic algorithms, which ensure to secure data communications from remote collection points of measurement, will be realized. These cryptographic algorithms will be realized in MATLAB and C/C++. The last part is focus on designed and implemented a simulation model to telemetry the power quality.