The main topic of the thesis is creation of formulas for the amount of information entropy in biometric characteristics of iris and retina. This field of science in biometrics named above is unstudied yet, so the thesis tries to initiate research in this direction. The thesis also discusses the historical context of security and identification fields according to biometric characteristics of a human being with an overlap for potential usage in biometrics of iris and retina. The Daugman’s algorithm for converting iris image into the binary code which can be used as a cryptographic key is discussed in detail. An application implementing this conversion is also a part of the thesis.

Confidential information such as passwords, cryptographic keys, certificates, etc. are used every day on various places. Mobile phone can be a good storage for such informations, but is necessary to ensure data security. Main goal of this project is to create a program for Windows Mobile phones which will keep all the informations in one place protected by password. Designed program lets user to store passwords, cryptographic keys, various files, important contacts, credit card numbers, etc. Some of the stored informations can be downloaded from remote server via FTP protocol or from smart card. It is also possible that two clients will synchronize their informations via Network and other usefull functions.

V této práci vytváříme jednoduchý systém pro rychlou textovou komunikaci (IM), který využívá technologii Near-Field Communication (NFC) ke zlepšení bezpečnosti a soukromí. V první části zkoumáme samotnou technologii NFC. Poté se věnujeme možnostem NFC v operačním systému Android pro chytrá mobilní zařízení a také existujícím aplikacím, které tyto možnosti využívají. Rovněž zkoumáme nejmodernější přístup k bezpečnému IM, zejména Signal Protocol a jeho open-source implementaci pro Android. Dále pak navrhujeme IM systém, který používá Signal Protocol pro šifrování zpráv a NFC pro výměnu kryptografického materiálu, aniž by vyžadoval použití telefonních čísel nebo důvěryhodnou třetí stranu. Nakonec předkládáme vzorovou implementaci klientské i serverové aplikace a zhodnocení vlastností tohoto systému z hlediska soukromí a bezpečí.

The dissertation thesis deals with cryptographic protocols for secure authentication of communicating parties, which are intended primarily for low-cost devices used in Internet of Things. Low-cost devices represent computationally, memory and power constrained devices. The thesis focuses mainly on the possibilities of using mathematically undemanding cryptographic resorces for ensuring integrity of transmitted dat, authenticity of and secured transmission of data on low-cost devices. The main goals of the thesis focus on the design of new advanced cryptographic protocols for ensuring integrity of transmitted data, authenticity, confidentiality of transmitted data between low-cost devices and authenticity with non-repudiation of done events. The thesis describes proposal of three authentication protocols, one unilateral authentication protocol and two mutual authentication protocols. The thesis also describes proposals of two protocols for secured transmission of data between two devices, one protocol without a proof of receipt data and one protocol with proof of receipt data. In this thesis is also performed a security analysis and a discussion to proposed protocols.

This master thesis deals with an implementation of Diffie-Hellman protocol on smart card which is based on MULTOS OS. Defines the smart cards based on MULTOS OS and their usage. Output of this thesis are applications for a smart card and for a client using Diffie-Hellman protocol for establishing of a secret key between two communication sides through unsecured communication channel.

Le problème d’´équivalence de code joue un rôle important dans la théorie de code et la cryptographie basée sur le code. Cela est dû à son importance dans la classification des codes ainsi que dans la construction et la cryptanalyse des cryptosystèmes à base de codes. Il est également lié à un problème ouvert d’isomorphisme de graphes, un problème bien connu dans le domaine de la théorie de la complexité. Nous prouvons pour les codes ayant un hull trivial qu’il existe une réduction polynomiale de l’équivalence par permutation de codes à l’isomorphisme de graphes. Cela montre que cette sous-classe d’équivalence de permutation n’est pas plus dure que l’isomorphisme de graphes. Nous introduisons une nouvelle méthode pour résoudre le problème d’équivalence de code. Nous développons des approches algébriques pour résoudre le problème dans ses deux versions : en permutation et en diagonale. Nous construisons un système algébrique en établissant des relations entre les matrices génératrices et les matrices de parité des codes équivalents. Nous nous retrouvons avecun système plusieurs variables d’équations linéaires et quadratiques qui peut être résolu en utilisant des outils algébriques tels que les bases de Groebner et les techniques associées. Il est possible en théorie de résoudre l’équivalence de code avec des techniques utilisant des bases de Groebner. Cependant, le calcul en pratique devient complexe à mesure que la longueur du code augmente. Nous avons introduit plusieurs améliorations telles que la linéarisation par bloc et l’action de Frobenius. En utilisant ces techniques, nous identifions de nombreux cas où le problème d’équivalence de permutation peut être résolu efficacement. Notre méthode d’équivalence diagonale résout efficacement le problème dans les corps de petites tailles, à savoir F3 et F4. L’augmentation de la taille du corps entraîne une augmentation du nombre de variables dans notre système algébrique, ce qui le rend difficile à résoudre. Nous nous intéressons enfin au problème d’isomorphisme de graphes en considérant un système algébrique quadratique pour l’isomorphisme de graphes. Pour des instances tirées aléatoirement, le système possède des propriétés intéressantes en termes de rang de la partie linéaire et du nombre de variables. Nousrésolvons efficacement le problème d’isomorphisme de graphes pour des graphes aléatoires avec un grand nombre de sommets, et également pour certains graphes réguliers tels que ceux de Petersen, Cubical et Wagner.123 / Code equivalence problem plays an important role in coding theory and code based cryptography.That is due to its significance in classification of codes and also construction and cryptanalysis of code based cryptosystems. It is also related to the long standing problem of graph isomorphism, a well-known problem in the world of complexity theory. We introduce new method for solving code equivalence problem. We develop algebraic approaches to solve the problem in its permutation and diagonal versions. We build algebraic system by establishing relations between generator matrices and parity check matrices of the equivalent codes. We end up with system of multivariables of linear and quadratic equations which can be solved using algebraic tools such as Groebner basis and related techniques. By using Groebner basis techniques we can solve the code equivalence but the computation becomes complex as the length of the code increases. We introduced several improvements such as block linearization and Frobenius action. Using these techniques we identify many cases where permutation equivalence problem can be solved efficiently. Our method for diagonal equivalence solves the problem efficiently in small fields, namely F3 and F4. The increase in the field size results in an increase in the number of variables in our algebraic system which makes it difficult to solve. We introduce a new reduction from permutation code equivalence when the hull is trivial to graph isomorphism. This shows that this subclass of permutation equivalence is not harder than graph isomorphism.Using this reduction we obtain an algebraic system for graph isomorphism with interesting properties in terms of the rank of the linear part and the number of variables. We solve the graph isomorphism problem efficiently for random graphs with large number of vertices and also for some regular graphs such as Petersen, Cubical and Wagner Graphs.

Cette thèse s'articule autour de l'étude de la cohérence de la lumière produite à partir de sources de paires de photons intriqués et de micro-lasers. Nous avons produit et manipulé des états photoniques intriqués, et conduit des investigations à la fois fondamentales et appliquées. Les deux études menées sur les aspects fondamentaux de la non localité avaient pour but de relaxer partiellement deux contraintes sur lesquelles s'appuie l'inégalité de Bell standard en vue d'applications à la cryptographie quantique. Ainsi, en collaboration avec l'Université de Genève, nous avons redéfini la notion de localité en prenant en compte les influences sur les mesures de corrélations des choix des configurations expérimentales et d'une efficacité globale de détection limitée. Cela a permis de définir des inégalités de Bell généralisées et les violations expérimentales qui en découlent permettent d'attester de la non localité des états quantiques observés. Nous avons aussi étudié et mis en place une solution expérimentale autorisant l'émission de photons intriqués dans des pairs de canaux télécoms pour la cryptographie quantique. Nous avons montré la préservation de l'intrication sur 150 km et obtenu des débits records en comparaison avec les réalisations similaires. Enfin, nous avons étudié les propriétés de l’émission de lasers à semi-conducteurs aux dimensions réduites. L’émission de ces composants microscopiques s'accompagne de grandes fluctuations en intensité lorsque ceux-ci sont pompés en-dessous du seuil laser. Cette étude a permis de mieux comprendre comment se construit la cohérence laser dans ces systèmes. / In this thesis we study the coherence of light emitted by entangled photon-pair sources and micro-lasers. We have generated an manipulated entangled photonic states and investigated both fundamental (non locality) and applied (quantum cryptography) research directions. The objective of two fundamental studies on non locality was to partially relax the strong assumptions on which standard Bell tests rely. To this end, we redefined, in collaboration with the University of Geneva, the formalism of locality taking into account the influence, on correlation measurements, of the freedom of choice (in the basis settings) and of the limitation of the overall detection efficiency. Both assumptions allow devising generalized Bell inequalities whose experimental violations indicate that we can still attest for non locality for the observed states. In addition, we have studied and realized an experimental setup allowing to distribute entangled photon pairs in paired telecom channels for high bit rate quantum cryptography. We have shown that entanglement is preserved over a distance of 150 km with record rates for similar realizations, by mimicking classical network solutions exploiting, in an optimal fashion, the capacity of an optical fiber link via dense spectral multiplexing. Finally, we have studied the properties of light emitted by semiconductor lasers showing reduced dimensionality. This micro-lasers actually provide output light under high intensity fluctuations when they are pumped below the threshold. Their study allowed to refine our understanding on how the coherence builds up in these systems as the cavity is filled with photons.

Continuation of the 12th part: Complement and correction of the novel Tietken-Castell-Prime-Algorithm

In today’s society, especially after everything that was reported by Edward Snowden when he, during 2013, showed how USA’s NSA worked with global surveillance, there is a great need to keep communication secure. Se- cure both in such a way that the contents in messages are protected from unwanted parties as well as in such a way that messages’ authenticity can be verified. It’s just as important to know who one is communicating with as it is to know that no unauthorized person can read material not meant for them. We see more and more solutions like for instance Let’s Encrypt that offer free encryption for web traffic but when it actually comes to SMS traffic there aren’t as many effective options available. The purpose of this work is to develop a system to examine how one most effectively could treat SMS in a secure and authenticated fashion. The goal is to, contrary to many other solutions, not be dependent upon a third party but rather utilize the existing SMS protocol and to make sure that the con- tents is encrypted by use of public key cryptography. This leads to it being enough to use the application to be able to communicate securely as there would be no central server that could be closed down or in other ways af- fected to lessen the security of the communication. We also get a system that is much less dependent on mobile data and will thus become more flexible in areas where this can be costly or hard to reach. Beyond this a system for verification of external keys will be explored. Even if it, in case the user chooses to use it, will need access to mobile data, it could be a useful tool for authentication of communication with parties with whom one has not been in contact with before since they can publish their public key and then refer to it within the message. An example use case for this would be a gov- ernment needing to publish information to its citizens; then this key can be published on their web site so that anyone easily could verify it (the goal is to have this be done automatically during message retrieval). / I dagens samhälle, särskilt efter bland annat allt som rapporterades av Ed- ward Snowden när han under 2013 påvisade hur USAs NSA jobbade med global övervakning, är det av stor vikt av att kommunikation bör hållas säker. Säker både på så sätt att innehållet i meddelanden skyddas från oön- skade personer och på så sätt att meddelandens autenticitet kan styrkas. Det är minst lika viktigt att veta vem man kommunicerar med som att veta att ingen obehörig kan läsa material som inte är ämnat för dem. Vi ser fler och fler lösningar som till exempel Let’s Encrypt som erbjuder gratis kryptering av webbtrafik men när det gäller just SMS-trafik finns inte lika många och effektiva lösningar. Syftet med det här arbetet är att utveckla ett system för att undersöka hur man på bästa sätt skulle kunna behandla SMS på ett säkert och autentis- erat sätt. Målet är att, till skillnad mot många andra lösningar, inte vara beroende av en tredje part utan istället nyttja det befintliga SMS-protokollet men se till att innehållet är krypterat med hjälp av public key cryptography. Detta leder till att det räcker att använda applikationen för att kunna kom- municera säkert, det finns ingen central server som skulle kunna stängas ner eller på andra sätt påverkas för att försämra kommunikationens säker- het. Vi får också ett system som är mycket mindre beroende av mobildata och blir därför mer flexibelt i områden där dessa kan vara kostsamma eller svåråtkomliga. Utöver detta kommer ett system för extern autentisering av nycklar undersökas. Även om detta, om avsändaren väljer att utnyttja det, kommer att kräva tillgång till mobil datatrafik så skulle det vara ett nyttigt verktyg för att kunna autentisera kommunikation med personer som man aldrig tidigare varit kontakt med då dessa i så fall kan publicera sin nyckel online och sedan hänvisa till den i meddelandet. Exempel på användning för detta är om en myndighet behöver gå ut med information till medbor- garna; då kan denna nyckel publiceras på dess webbsida så att alla enkelt kan kontrollera den (målet är i så fall att detta skall ske automatiskt under hämtning av ett meddelande).

Internet of Things (IoT) refers to an inter-connected world where physical devices are seamlessly integrated into the Internet and become active participants of business, information and social processes. This involves the inter-connection of a large number of heterogeneous networked entities and networks. Emergence of technologies such as Zigbee, Bluetooth low energy and embedded sensors has transformed simple physical devices into smart objectsthat can understand and react to their environment. Such smart objects form the building blocks for the Internet of Things. The communication infrastructure for these objects is based on an extension of the Internet protocol stack. Although the need for security is widely accepted, there is no clear consensus on how IP-based Internet security protocols can be applied to resource-constrained smart object networks. In this thesis  we develop a new secure and energyefficient communication model for the Constrained Application Protocol (CoAP), a light-weight communication protocol designed for smart object networks. We contribute to the standardization of the generic communication architecture by adding security and delegation components for smart objects that sleep for large amounts of time during their operational phase. This architecture ensures data integrity and authenticity over a multi-hop network topology. It also provides a mirroring mechanism that uses a proxy to serve data on behalf of sleeping smart objects, thereby allowing them to act as always-online web servers. A working prototype implementation of the architecture is also developed. The security features in the architecture presented in this thesis are based on using strong public-key cryptography. Contrary to popular belief, our performance evaluation shows that asymmetric public-key cryptography can be implemented on small 8-bit micro-controllers without modifying the underlying cryptographic algorithms. / Internet of Things (IoT, ”Föremålens Internet") syftar på en sammankopplad värld där fysiska apparater är sömlöst integrerade till Internet och blir aktiva deltagare i affärslivs-, informations- och sociala processer. Detta innefattar sammankopplingen av ett stort antal heterogeniskt nätverkade enheter och nätverk. Uppkomsten av teknologier som Zigbee, låg energi Bluetooth och inbyggda sensorer har förvandlat enkla fysiska apparater till smarta objekt som kan förstå och reagera till sin omgivning. Dessa smarta objekt utgör byggstenarna för Föremålens Internet. Kommunikationsinfrastrukturen för dessa objekt bygger på en utvidgning av internetprotokollstacken.  Även om behovet av säkerhet är allmänt känt, finns det inget konsensus om hur IP-baserade internetsäkerhetsprotokoll kan tillämpas i resursbegränsade smartobjektnätverk. I denna avhandling utvecklas en ny säker och energisnål kommunikationsmodell för Constrained Application Protocol (CoAP, “Begränsat applikationsprotokoll"), ett lätt kommunikationsprotokoll avsett för smartobjektnätverk. Avhandlingen bidrar till standardiseringen av den generiska kommunikationsarkitekturen genom att tillsätta säkerhets- och delegationskomponenter för smarta objekt som sover under en stor del av sin operativa fas. Denna arkitektur garanterar dataintegritet och autenticitet över en flerhopps nätverkstopologi. Arkitekturen bidrar också med en återspeglingsmekanism som använder sig av en proxyserver för att erbjuda data för sovande smarta objekts del, vilket låter dem agera som alltid-online webbservrar. I avhandlingen utvecklas också en fungerande prototypimplementation av arkitekturen. Säkerhetsegenskaperna i den arkitektur som presenteras i denna avhandling är baserade på användningen av stark publik-nyckel kryptering. I motsatts till den allmänna förväntningen, visar prestationsbedömningen i denna avhandling att asymmetrisk kryptering med publik nyckel kan tillämpas i 8-bitars mikrokontrollrar utan att ändra på de underliggande kryptografiska algoritmerna.