Submitted by Daniele Amaral (daniee_ni@hotmail.com) on 2016-09-15T16:05:03Z No. of bitstreams: 1 DissWCCJ.pdf: 1969639 bytes, checksum: cbe6746c0279668ba7ff3b8de72d8caf (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-16T19:51:53Z (GMT) No. of bitstreams: 1 DissWCCJ.pdf: 1969639 bytes, checksum: cbe6746c0279668ba7ff3b8de72d8caf (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-16T19:51:57Z (GMT) No. of bitstreams: 1 DissWCCJ.pdf: 1969639 bytes, checksum: cbe6746c0279668ba7ff3b8de72d8caf (MD5) / Made available in DSpace on 2016-09-16T19:52:02Z (GMT). No. of bitstreams: 1 DissWCCJ.pdf: 1969639 bytes, checksum: cbe6746c0279668ba7ff3b8de72d8caf (MD5) Previous issue date: 2015-08-21 / Não recebi financiamento / Cryptography is a fascinating topic, concerning the practical point of view, and it is useful to access bank accounts, e-mails and social networks. According to this perspective, this study aimed to show how simple it may be to make use of cryptography. It was proved, through the work performed, that it is possible for students from elementary and high school to encrypt and decrypt messages using R.S.A. Cryptography, which involves the concept of creating public keys and private keys for the encryption of messages. A simple but powerful activity on the utility view was assigned to show students from the 9th grade of elementary school and from the 1st and 2nd years of high school from a private school in São Paulo State how interesting and pleasurable the use of Mathematics can be. Such activities are not usually present in the traditional didactic materials. The theoretical tools, containing theorem and corollaries, as well as their demonstrations, which mathematically justify the validity of techniques and the algorithm used on R.S.A. Cryptography will be presented. The activities do not assume sophisticated prerequisites and can be applied in the classroom, in real situations, so that the students can appreciate the beauty of Mathematics. / A criptografia é um assunto fascinante do ponto de vista prático; é útil para acessar contas bancárias, e-mails e redes sociais. Segundo esta perspectiva, esta dissertação baseou-se em mostrar o quão simples pode ser a utilização da criptografia. No trabalho realizado foi mostrado que é possível, para alunos do Ensino Fundamental e Médio, codificar e decifrar mensagens utilizando a criptografia - RSA, a qual envolve o conceito da criação de chaves públicas e chaves privadas para a codificação de mensagens. Uma atividade simples, porém importante do ponto de vista utilitário, foi aplicada para mostrar aos alunos do 9º ano do Ensino Fundamental, da 1ª e 2ª séries do Ensino Médio de uma escola particular do interior paulista para mostrar o quão interessante e prazerosa pode ser a utilização da Matemática. Tais atividades não constam usualmente nos materiais didáticos tradicionais. Nesta dissertação será apresentado o ferramental teórico, contendo teoremas e corolários, assim como suas demonstrações, os quais justificam, matematicamente, a validade das técnicas e do algoritmo utilizados na criptografia – RSA. As atividades não pressupõem pré-requisitos sofisticados, podendo ser aplicadas em sala de aula, em situações reais, para que os alunos apreciem a beleza da Matemática.

Bitcoin har framträtt som den mest igenkännbara kryptovalutan sedan igångsättningen 2009 och har vid skrivande tillfälle ett börsvärde på 1,6 biljoner svenska kronor. Detta ihop med den ekonomiska friheten som Bitcoin erbjuder gör att användarantalet ständigt ökar. Likt all ny teknik så tar det tid innan teknologin är fullt utvecklad och anpassad för den bredda massan. I följd av detta kan säkerheten lida vilket kan resultera till ekonomiska förluster. Denna forskningsinsats undersöker vad för åtgärder och strategier som kan användas för att öka säkerheten via en litteraturstudie. Insatsen undersöker även med hjälp av en enkätundersökning ställd till ett Bitcoin-forum om hur användare av Bitcoin hanterar sina privata nycklar. Arbetet visar att det finns åtgärder som bidrar till ökad säkerhet såsom kryptering och multisignatur men att det hänger mycket på vad användarna själva väljer för typ av bäst strategi för deras användningsområde. Enkätundersökning redovisar att majoriteten av användarna gör säkerhetsmedvetna beslut för hur de använder Bitcoin men att en andel nyttjar mindre önskade tillvägagångssätt. / Bitcoin has emerged as the most recognizable cryptocurrency since its inception in 2009 and, at the time of writing has a market capitalization of 165 billion dollars. This together with the financial freedom that Bitcoin offers means that the number of users is constantly increasing. Like all new technology, it takes time for the technology to be fully developed and adapted to the wider mass. As a result, security can suffer which can result in financial losses. This research effort explores what measures and strategies can be used to increase safety through a literature study. The effort also investigates with the help of a survey conducted at a Bitcoin forum on how users of Bitcoin manage their private keys. The work shows that there are measures that contribute to increased security such as encryption and multi-signature but that much depends on what the users themselves choose for the type of best strategy for their area of use. The survey shows that the majority of users make security-conscious decisions about how to use Bitcoin but that aproportion uses less desirable approaches.