Made available in DSpace on 2017-07-21T20:56:28Z (GMT). No. of bitstreams: 1 Jose Robyson Aggio Molinari.pdf: 837254 bytes, checksum: a577b2742ab4df347179d61529e63767 (MD5) Previous issue date: 2016-02-03 / This study presents some of the encryption methods used in antiquity as well as the advance in the way of encrypting. The main objective of this work is the study of RSA Method: its Historical context, the importance of prime numbers, the inefficiency of factorization algorithms, coding, decoding, its security and a study of the Euler function. Some activities with mathematical content related to encryption have been developed. Thus, it is expected that this research can present an auxiliary methodology for teaching certain math content, linked to the utilization of cryptography. / Este trabalho apresenta alguns métodos de criptografia utilizados na antiguidade e também o avanço na maneira de criptografar. O objetivo principal é o estudo do Método RSA: contextualização histórica, a importância dos números primos, a ineficiência dos algoritmos de fatoração, codificação, decodificação, a segurança e um estudo sobre a função de Euler. Desenvolveu-se algumas atividades com conteúdos matemáticos relacionadas à criptografia. Desta maneira, espera-se que esta pesquisa possa apresentar uma metodologia auxiliar para o ensino de certos conteúdos da matemática, articulados com a utilização da criptografia.

Estudamos a criptografia RSA como uma importante aplicação dos números primos e da aritmética modular. Apresentamos algumas sugestões de atividades relacionadas ao tema a serem desenvolvidas em sala de aula nas séries finais do ensino fundamental / We studied RSA cryptography as an important application to prime numbers and modular arithmetic. We present some suggestions of activities related to the subject to be developed in classrooms of the final years of elementary school vii

A digital signature is the electronic counterpart to the hand written signature. It can prove the source and integrity of any digital data, and is a tool that is becoming increasingly important as more and more information is handled electronically. Digital signature schemes use a pair of keys. One key is secret and allows the owner to sign some data, and the other is public and allows anyone to verify the signature. Assuming that the keys are large enough, and that a secure scheme is used, it is impossible to find the private key given only the public key. Since a signature is valid for the signed message only, this also means that it is impossible to forge a digital signature. The most well-used scheme for constructing digital signatures today is RSA, which is based on the hard mathematical problem of integer factorization. There are, however, other mathematical problems that are considered even harder, which in practice means that the keys can be made shorter, resulting in a smaller memory footprint and faster computations. One such alternative approach is using elliptic curves. The underlying mathematical problem of elliptic curve cryptography is different to that of RSA, however some structure is shared. The purpose of this thesis was to evaluate the performance of elliptic curves compared to RSA, on a system designed to efficiently perform the operations associated with RSA. The discovered results are that the elliptic curve approach offers some great advantages, even when using RSA hardware, and that these advantages increase significantly if special hardware is used. Some usage cases of digital signatures may, for a few more years, still be in favor of the RSA approach when it comes to speed. For most cases, however, an elliptic curve system is the clear winner, and will likely be dominant within a near future. / En digital signatur är den elektroniska motsvarigheten till en handskriven signatur. Den kan bevisa källa och integritet för valfri data, och är ett verktyg som blir allt viktigare i takt med att mer och mer information hanteras digitalt. Digitala signaturer använder sig av två nycklar. Den ena nyckeln är hemlig och tillåter ägaren att signera data, och den andra är offentlig och tillåter vem som helst att verifiera signaturen. Det är, under förutsättning att nycklarna är tillräck- ligt stora och att det valda systemet är säkert, omöjligt att hitta den hemliga nyckeln utifrån den offentliga. Eftersom en signatur endast är giltig för datan som signerades innebär detta också att det är omöjligt att förfalska en digital signatur. Den mest välanvända konstruktionen för att skapa digitala signaturer idag är RSA, som baseras på det svåra matematiska problemet att faktorisera heltal. Det finns dock andra matematiska problem som anses vara ännu svårare, vilket i praktiken innebär att nycklarna kan göras kortare, vilket i sin tur leder till att mindre minne behövs och att beräkningarna går snabbare. Ett sådant alternativ är att använda elliptiska kurvor. Det underliggande matematiska problemet för kryptering baserad på elliptiska kurvor skiljer sig från det som RSA bygger på, men de har en viss struktur gemensam. Syftet med detta examensarbete var att utvärdera hur elliptiska kurvor presterar jämfört med RSA, på ett system som är designat för att effektivt utföra RSA. De funna resultaten är att metoden med elliptiska kurvor ger stora fördelar, även om man nyttjar hårdvara avsedd för RSA, och att dessa fördelar ökar mångfaldigt om speciell hårdvara används. För några användarfall av digitala signaturer kan, under några år framöver, RSA fortfarande vara fördelaktigt om man bara tittar på hastigheten. För de flesta fall vinner dock elliptiska kurvor, och kommer troligen vara dominant inom kort.

Submitted by Fernando Souza (fernandoafsou@gmail.com) on 2017-08-21T11:30:58Z No. of bitstreams: 1 arquivototal.pdf: 1795088 bytes, checksum: fb7c00f2437bd31139648401e67e1ad9 (MD5) / Made available in DSpace on 2017-08-21T11:30:58Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1795088 bytes, checksum: fb7c00f2437bd31139648401e67e1ad9 (MD5) Previous issue date: 2014-07-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work the problem of routing and route allocation (RSA) for elastic optical networks has been studied. This is similar to the problem of routing and wavelength allocation problem, the latter being characteristic routed optical networks in wavelengths. The problem RSA aims to allocate the least amount of resources to elastic optical network so it can cater to the maximum number of demands set out in customer traffic matrix. Besides the study of the problem, in this paper, two metaheuristics were implemented, which were the Iterated Local Search (ILS) and the Greedy Randomized Adaptive Search Procedure (GRASP), which use SSA and LP-CA mathematical models in the local search phase. To implement metaheuristics and mathematical models, we used IBM ILOG CPLEX IDE. The results are presented in graphs, which showed that metaheuristics able to be efficient and competitive, with good quality solutions in an acceptable and even lower than the results presented by accurate modeling computational time. Finally, this paper presents a discussion of the advantages and limitations of this study, and presents directions for future work in this field of study. / Neste trabalho foi estudado o problema de roteamento e alocação de rota (RSA) em redes ópticas elásticas. Este é um problema similar ao problema de roteamento e alocação de comprimentos de onda, este último sendo característico em redes ópticas roteadas em comprimentos de onda. O problema RSA tem como objetivo atribuir a menor quantidade de recursos de uma rede óptica elástica de tal forma que consiga atender ao máximo número de demandas definidas na matriz de tráfego cliente. Além do estudo sobre o problema, neste trabalho foram implementadas duas metaheurísticas, sendo elas o Iterated Local Search (ILS) e o Greedy Randomized Adaptative Search Procedure (GRASP), as quais utilizam os modelos matemáticos SSA e LP-CA na fase de busca local. Para implementar os modelos matemáticos e metaheurísticas, foi utilizada a IDE IBM iLOG CPLEX. Os resultados obtidos são apresentados através de gráficos, os quais demonstraram que as metaheurísticas conseguiram ser eficientes e competitivas, apresentando soluções de boa qualidade em um tempo computacional aceitável e até menor que os resultados apresentados pelos modelos exatos. Por fim, este texto apresenta uma discussão sobre os diferenciais e limitações deste trabalho, e apresenta direcionamentos para trabalhos futuros neste campo de estudo.

Estudamos a criptografia RSA como uma importante aplicação dos números primos e da aritmética modular. Apresentamos algumas sugestões de atividades relacionadas ao tema a serem desenvolvidas em sala de aula nas séries finais do ensino fundamental / We studied RSA cryptography as an important application to prime numbers and modular arithmetic. We present some suggestions of activities related to the subject to be developed in classrooms of the final years of elementary school vii

Em 2009, N. Heninger e H. Shacham apresentaram um algoritmo de reconstrução que permite recuperar a chave secreta sk do criptossistema RSA básico em tempo polinomial tendo em forma aleatória 27 % dos seus bits. Sabemos que podemos obter uma versão com erros (bits modicados) da chave secreta RSA graças aos ataques cold boot. O algoritmo apresentado por Heninger-Shacham corrige esses erros fazendo uso das relações matemáticas que existe entre as chaves pública e secreta do criptossistema RSA básico. O objetivo deste trabalho é estudar esse algoritmo para implementar e analisar seu análogo para o criptossistema RSA multi-primo. Os resultados obtidos mostram que para reconstruir a chave secreta sk do criptossistema RSA u-primos é preciso ter uma fração de bits corretos maior a 2 - 2^((u+2)/(2u+1)), mostrando assim que a segurança oferecida pelo criptossistema RSA multi-primo (u>/ 3) é maior com relação ao criptossistema RSA básico (u = 2). / In 2009, N. Heninger and H. Shacham presented an algoritm for reconstructing the secret key sk of the basic RSA cryptosystem in polynomial time With a fraction of random bits greater or equal to 0.27 of its bits. We know that secret key with errors sk can be obtained from DRAM using cold-boot attacks. The Heninger and Shacham\'s algorithm xes these errors using the redundancy of secret and public key of basic RSA cryptosystem. In this work, the topic is to study this algoritm to implement and analyze its analogous for the multi-prime RSA cryptosystem. Our obtained results show the secret key sk of multi-prime RSA cryptosystem can be Reconstructed having a fraction equal or greater than 2 - 2^((u+2)/(2u+1)) of random bits. therefore the security of multi-prime RSA cryptosystem (u >/ 3) is greater than basic RSA cryptosystem (u = 2).

The master’s thesis is focusing on electronization of worldwide known game geocaching. It contains introduction to classic geocashing, analysis of current status and outline of possible solution. The design of electronization is based on smart card Gemalto. Very important part of the thesis is cryptographic security, therefore there is explanation of symetric and asymetric cryptography. The digital signature of transmitted message is realized by RSA algorithm, which is supported by the Gemalto smart card. Due to future expandability, it is appropriate to use general protocol. For this reason was chosen the ACP protocol which the supervisor of thesis adviced. In the following part, there is introduction to smart cards, their types and detailed description of Gemalto smart card. In the chapter 7 starts the solution of this issue and there are described the programmed apps.

Depuis 2011, pas moins de 7 nouvelles thérapies ont été acceptées pour le traitement du mélanome métastatique. Ces nouvelles thérapies, composées de 4 inhibiteurs de B-Raf et MEK et de 3 anticorps, ont amélioré significativement la durée de vie des patients. Néanmoins, la forme résistante de la maladie est toujours problématique et aucun traitement à l’heure actuelle ne permet d’éradiquer la maladie. Dans ce contexte, ces travaux présentent la synthèse et la caractérisation de nouveaux dérivés 4-phényl-2-aminothiazole, actifs contre les formes résistantes du mélanome. 3 points structuraux clés ont été modulés : les extrémités (position 2 du thiazole et positions 3 et 4 du noyau phényle) et le coeur bis-aryle du squelette. Les analogues synthétisés ont été évalués sur des cellules A375 de mélanome pour étudier les relations structure-activités de cette nouvelle série de dérivés. Des dérivés jusqu’à 10 fois plus actifs que le hit initial ont été développés. La cible moléculaire de cette nouvelle série a été identifiée et le mode d’action caractérisé. Il s’agit de GRP78, une protéine chaperonne dont l’inhibition provoque un fort niveau d’activation de la voie de l’unfolded protein response, menant à la mort cellulaire par un mécanisme concomitant d’apoptose et d’autophagie. Ce mode d’action innovant permet à cette série d’être active contre plusieurs formes de cancers (mélanome, pancréas, LMC, colon etc.) indépendamment du statut mutationnel. A l’issue de ces travaux, un potentiel candidat clinique a été identifié et pourrait être évalué ultérieurement pour le traitement de cancers résistants et agressifs / Since 2011, 7 new anti-melanoma therapies have been approved. They are composed of 4 B-Raf or MEK inhibitors and 3 antibodies, and allowed considerable improvements in the patients’ life span. Nevertheless, the treatment of the resistant form of the melanoma is still an unmet challenge. In this context, this manuscript reports the synthesis and the characterization of new 4-phenyl-2-aminothiazole derivatives active against resistant melanoma. We focused our attention on the modification of the position 2 of the thiazole, the positions 3 and 4 of the phenyl ring, and finally the bis-aryl core. Several derivatives were synthetized and assessed against A375 melanoma cells to depict the structure-activity relationship studies of this new series. Thus, we succeeded in a 10-fold improvement in cytotoxic activity against cancer cells compared with the initial hit, reaching a 0.5 μM EC50 against A375 cell line. Strikingly, lead derivative exerted strong in vivo anti-tumoral activity in mice tumor xenograft experiments. This new series of compound inhibits GRP78, a chaperone protein, resulting in the strong activation level of unfolded protein response and leading to cell death by concomitant apoptotic and autophagy mechanisms. This innovative mode of action confers to our compounds a high cytotoxic activity on various cancer cells (melanoma, pancreatic, CML, colon etc.), regardless to their mutational status. Ultimately, we found a potential clinical candidate that could embody a new solution for the treatment of resistant and aggressive forms of cancer

This thesis project examines the performance limitations of Hardware Security Module (HSM) devices with respect to fulfilling the needs of security services in a rapidly growing security market in a cost-effective way. In particular, the needs due to the introduction of a new electronic ID system in Sweden (the Federation of Swedish eID) and how signatures are created and managed. SafeNet Luna SA 1700 is a high performance HSM's available in the current market. In this thesis the Luna SA 1700 capabilities are stated and a comprehensive analysis of its performance shows a performance gap between what HSMs are currently able to do and what they need to do to address the expected demands. A case study focused on new security services needed to address Sweden's e Identification organization is presented. Based upon the expected performance demands, this thesis project proposes an optimized HSM solution to address the identified performance gap between what is required and what current HSMs can provide. A series of tests were conducted to measure an existing HSM's performance. An analysis of these measurements was used to optimize a proposed solution for selected HSM or similar HSMs. One of the main requirements of the new signing service is the capability to perform fifty digital signatures within the acceptable response time which is 300 ms during normal hours and 3000 ms during peak hours. The proposed solution enables the HSM to meet the expected demands of 50 signing request per second in the assumed two hours of peak rate at a cost that is 1/9 of the cost of simply scaling up the number of HSMs. The target audience of this thesis project is Security Service Providers who use HSMs and need a high volume of key generation and storing. Also HSM vendors consider this solution and add similar functionality to their devices in order to meet the desired demands and to ensure a better future in this very rapidly growing market. / Detta examensarbete undersöker prestandabegränsningar för Hardware Security Module (HSM) enheter med avseende på att uppfylla behov av säkerhetstjänster i en snabbt växande marknad och på ett kostnadseffektivt sätt. I synnerhet på grund av de säkerhetskrav som nu existerar/tillkommit efter införandet av ett nytt elektroniskt ID-system i Sverige (Federationen för Svensk eID) och hur underskrifter skapas och hanteras. SafeNet Luna SA 1700 är en högpresterande HSM enhet tillgänglig på marknaden. I den här avhandlingen presenteras nuvarande HSM kapacitet och en omfattande analys av resultatet visar ett prestanda gap mellan vad HSMS för närvarande kan göra och vad som behöver förbättras för att ta itu med de förväntade kraven. En fallstudie fokuserad på nya säkerhetstjänster som krävs i och med Sveriges nya e-Identifiering presenteras. Baserat på resultatet i den här avhandlingen föreslås en optimerad HSM lösning för att tillgodose prestanda gapet mellan vad HSM presterar och de nya krav som ställs. Ett flertal tester genomfördes för att mäta en befintlig HSM prestanda. En analys av dessa mätningar användes för att föreslå en optimerad lösning för HSMS (eller liknande) enheter. Ett av de huvudsakliga kraven för den nya signeringstjänsten är att ha en kapacitet av 50 digitala signaturer inom en accepterad svarstidsintervall, vilket är 300ms vid ordinarie trafik och 3000ms vid högtrafik. Förslagen i avhandlingen möjliggör HSM enheten att tillgodose kraven på 50 signeringen per sekund under två timmars högtrafik, och till en 1/9 kostnad genom att skala upp antalet HSMs. Målgruppen i den här avhandlingen är användare av HSMs och där behovet av lagring och generering av nycklar i höga volymer är stort. Även HSM leverantörer som kan implementera den här optimeringen/lösningen i befintlig funktionalitet för att tillgodose det här behovet i en alltmer växande marknad.

Depuis les années 90, les attaques par canaux auxiliaires ont remis en cause le niveau de sécurité des algorithmes cryptographiques sur des composants embarqués. En effet, tout composant électronique produit des émanations physiques, telles que le rayonnement électromagnétique, la consommation de courant ou encore le temps d’exécution du calcul. Or il se trouve que ces émanations portent de l’information sur l’évolution de l’état interne. On parle donc de canal auxiliaire, car celui-ci permet à un attaquant avisé de retrouver des secrets cachés dans le composant par l’analyse de la « fuite » involontaire. Cette thèse présente d’une part deux nouvelles attaques ciblant la multiplication modulaire permettant d’attaquer des algorithmes cryptographiques protégés et d’autre part une démonstration formelle du niveau de sécurité d’une contre-mesure. La première attaque vise la multiplication scalaire sur les courbes elliptiques implémentée de façon régulière avec un masquage du scalaire. Cette attaque utilise une unique acquisition sur le composant visé et quelques acquisitions sur un composant similaire pour retrouver le scalaire entier. Une fuite horizontale durant la multiplication de grands nombres a été découverte et permet la détection et la correction d’erreurs afin de retrouver tous les bits du scalaire. La seconde attaque exploite une fuite due à la soustraction conditionnelle finale dans la multiplication modulaire de Montgomery. Une étude statistique de ces soustractions permet de remonter à l’enchaînement des multiplications ce qui met en échec un algorithme régulier dont les données d’entrée sont inconnues et masquées. Pour finir, nous avons prouvé formellement le niveau de sécurité de la contre-mesure contre les attaques par fautes du premier ordre nommée extension modulaire appliquée aux courbes elliptiques. / : Since the 1990s, side channel attacks have challenged the security level of cryptographic algorithms on embedded devices. Indeed, each electronic component produces physical emanations, such as the electromagnetic radiation, the power consumption or the execution time. Besides, these emanations reveal some information on the internal state of the computation. A wise attacker can retrieve secret data in the embedded device using the analyzes of the involuntary “leakage”, that is side channel attacks. This thesis focuses on the security evaluation of asymmetric cryptographic algorithm such as RSA and ECC. In these algorithms, the main leakages are observed on the modular multiplication. This thesis presents two attacks targeting the modular multiplication in protected algorithms, and a formal demonstration of security level of a countermeasure named modular extension. A first attack is against scalar multiplication on elliptic curve implemented with a regular algorithm and scalar blinding. This attack uses a unique acquisition on the targeted device and few acquisitionson another similar device to retrieve the whole scalar. A horizontal leakage during the modular multiplication over large numbers allows to detect and correct easily an error bit in the scalar. A second attack exploits the final subtraction at the end of Montgomery modular multiplication. By studying the dependency of consecutive multiplications, we can exploit the information of presence or absence of final subtraction in order to defeat two protections : regular algorithm and blinding input values. Finally, we prove formally the security level of modular extension against first order fault attacks applied on elliptic curves cryptography.