Biometric cryptosystem using online signatures

Biometric cryptosystems combine cryptography and biometrics to benefit from the strengths of both fields. In such systems, while cryptography provides high and adjustable security levels, biometrics brings in non-repudiation and eliminates the need to remember passwords or to carry tokens etc. In this work we present a biometric cryptosystems which uses online signatures, based on the Fuzzy Vault scheme of Jules et al. The Fuzzy Vault scheme releases a previously stored key when the biometric data presented for verification matches the previously stored template hidden in a vault. The online signature of a person is a behavioral biometric which is widely accepted as the formal way of approving documents, bank transactions, etc. As such, biometric-based key release using online signatures may have many application areas. We extract minutiae points (trajectory crossings, endings and points of high curvature) from online signatures and use those during the locking & unlocking phases of the vault. We present our preliminary results and demonstrate that high security level (128 bit encryption key length) can be achieved using online signatures

TWallet ARM TrustZone Enabled Trustable Mobile Wallet: A Case for Cryptocurrency Wallets

With the increasing popularity of Blockchains supporting virtual cryptocurrencies it has become more important to have secure devices supporting operations in trustable cryp- tocurrency wallets. These wallets, currently implemented as mobile Apps or components of mobile Apps must be protected from possible intrusion attacks. ARM TrustZone technology has made available an extension of the ARM processor ar- chitecture, allowing for the isolation of trusted and non-trusted execution environments. Critical components and their runtime support can be "booted" and loaded to run in the isolated execution environment, backed by the ARM processor. The ARM TrustZone solution provides the possible enforcement of security and privacy conditions for applica- tions, ensuring the containment of sensitive software components and data-management facilities, isolating them from OS-level intrusion attacks. The idea is that sensitive compo- nents and managed data are executed with a trust computing base supported at hardware and firmware levels, not affected by intrusions against non-protected OS-level runtime components. In this dissertation we propose TWallet: a solution designed as a generic model to sup- port secure and trustable Mobile Client Wallets (implemented as mobile Apps), backed by the ARM TrustZone technology. The objective is to manage local sensitive stored data and processing components in a trust execution environment isolated from the Android OS. We believe that the proposed TWallet framework model can also inspire other specific solutions that can benefit from the isolation of sensitive components in mobile Android Apps. As a proof-of-concept, we used the TWallet framework model to implement a trusted wallet application used as an Ethereum wallet, to operate with the Ethereum Blockchain. To achieve our goals, we also conducted different experimental observations to analyze and validate the solution, with the implemented wallet integrated, tested and validated with the Rinkeby Ethereum Test Network.Com o aumento da popularidade de Blockchains e utilização de sistemas de criptomoedas, tornou-se cada vez mais importante a utilização de dispositivos seguros para suportar aplicações de carteiras móveis (vulgarmente conhecidas por mobile wallets ou mobile cryptowallets). Estas aplicações permitem aos utilizadores uma gestão local, cómoda, confiável e segura de dados e operações integradas com sistemas de Blockchains. Estas carteiras digitais, como aplicações móveis completas ou como componentes de outras aplicações, têm sido desenvolvidas de forma generalizada para diferentes sistemas operativos convencionais, nomeadamente para o sistema operativo Android e para diferentes sistemas de criptomoedas. As wallets devem permitir processar e armazenar informação sensível associada ao controlo das operações realizadas, incluindo gestão e consulta de saldos de criptomoedas, realização e consultas de históricos de movimentos de transações ou consolidação do estado destas operações integradas com as Blockchains remotas. Devem também garantir o controlo seguro e confiável do processamento criptográfico envolvido, bem como a segurança das respetivas chaves criptográficas utilizadas. A Tecnologia ARM TrustZone disponibiliza um conjunto de extensões para as arquiteturas de processadores ARM, possibilitando o isolamento e execução de código num ambiente de execução suportado ao nível do hardware do próprio processador ARM. Isto possibilita que componentes críticos de aplicações ou de sistemas operativos suportados em processadores ARM, possam executar em ambientes isolados com minimização propiciada pelo isolamento da sua Base de Computação Confiável (ou Trusted Computing Base). A execução em ambiente seguro suportado pela solução TrustZone pode oferecer assim um reforço adicional de propriedades de confiabilidade, segurança e privacidade. Isto possibilita isolar componentes e dados críticos de possíveis ataques ou intrusões ao nível do processamento e gestão de memória ou armazenamento suportados pelo sistema operativo ou bibliotecas middleware, como é usual no caso de aplicações móveis, executando em ambiente Android OS ou noutros sistemas operativos de dispositivos móveis. Nesta dissertação propomos a solução TWallet, uma aproximação genérica para suporte de wallets utilizadas como aplicações móveis confiáveis em ambiente Android OS e fortalecidas pela utilização da tecnologia ARM TrustZone. O objetivo é possibilitar o isolamento de dados e componentes sensíveis deste tipo de aplicações, tornando-as mais seguras e confiáveis. Acreditamos que o modelo de desenho e implementação da solução TWallet, visto como uma framework de referência, poderá também ser utilizada no desenvolvimento de outras aplicações móveis em que o isolamento e segurança de componentes e dados críticos são requisitos semelhantes aos endereçados. Este pode ser o caso de aplicações de pagamento móvel, aplicações bancárias na área de mobile banking ou aplicações de bilhética na área vulgarmente chamada como mobile e-ticketing, entre outras. Como prova de conceito, utilizámos a TWallet framework para implementar um protótipo de uma wallet confiável, suportável em Android OS, para gestão de operações e criptomoedas na Blockchain Ethereum. A implementação foi integrada, testada e validada na rede Rinkeby Test Network - uma rede de desenvolvimento e testes utilizada como primeiro estágio de validação de aplicações e componentes para a rede Ethereum em operação real. Para validação da solução TWallet foi realizada uma avaliação experimen- tal. Esta avaliação envolveu a observação de indicadores de operação com verificação e comparação de diferentes métricas de operação e desempenho, bem como de alocação de recursos da aplicação protegida no modelo TWallet, comparando esses mesmo indicadores com o caso da mesma aplicação sem essa proteção

A trust supportive framework for pervasive computing systems

Recent years have witnessed the emergence and rapid growth of pervasive comput- ing technologies such as mobile ad hoc networks, radio frequency identification (RFID), Wi-Fi etc. Many researches are proposed to provide services while hiding the comput- ing systems into the background environment. Trust is of critical importance to protect service integrity & availability as well as user privacies. In our research, we design a trust- supportive framework for heterogeneous pervasive devices to collaborate with high security confidence while vanishing the details to the background. We design the overall system ar- chitecture and investigate its components and their relations, then we jump into details of the critical components such as authentication and/or identification and trust management. With our trust-supportive framework, the pervasive computing system can have low-cost, privacy-friendly and secure environment for its vast amount of services

The Prom Problem: Fair and Privacy-Enhanced Matchmaking with Identity Linked Wishes

In the Prom Problem (TPP), Alice wishes to attend a school dance with Bob and needs a risk-free, privacy preserving way to find out whether Bob shares that same wish. If not, no one should know that she inquired about it, not even Bob. TPP represents a special class of matchmaking challenges, augmenting the properties of privacy-enhanced matchmaking, further requiring fairness and support for identity linked wishes (ILW) – wishes involving specific identities that are only valid if all involved parties have those same wishes. The Horne-Nair (HN) protocol was proposed as a solution to TPP along with a sample pseudo-code embodiment leveraging an untrusted matchmaker. Neither identities nor pseudo-identities are included in any messages or stored in the matchmaker’s database. Privacy relevant data stay within user control. A security analysis and proof-of-concept implementation validated the approach, fairness was quantified, and a feasibility analysis demonstrated practicality in real-world networks and systems, thereby bounding risk prior to incurring the full costs of development. The SecretMatch™ Prom app leverages one embodiment of the patented HN protocol to achieve privacy-enhanced and fair matchmaking with ILW. The endeavor led to practical lessons learned and recommendations for privacy engineering in an era of rapidly evolving privacy legislation. Next steps include design of SecretMatch™ apps for contexts like voting negotiations in legislative bodies and executive recruiting. The roadmap toward a quantum resistant SecretMatch™ began with design of a Hybrid Post-Quantum Horne-Nair (HPQHN) protocol. Future directions include enhancements to HPQHN, a fully Post Quantum HN protocol, and more

TSKY: a dependable middleware solution for data privacy using public storage clouds

Dissertação para obtenção do Grau de Mestre em Engenharia InformáticaThis dissertation aims to take advantage of the virtues offered by data storage cloud based systems on the Internet, proposing a solution that avoids security issues by combining different providers’ solutions in a vision of a cloud-of-clouds storage and computing. The solution, TSKY System (or Trusted Sky), is implemented as a middleware system, featuring a set of components designed to establish and to enhance conditions for security, privacy, reliability and availability of data, with these conditions being secured and verifiable by the end-user, independently of each provider. These components, implement cryptographic tools, including threshold and homomorphic cryptographic schemes, combined with encryption, replication, and dynamic indexing mecha-nisms. The solution allows data management and distribution functions over data kept in different storage clouds, not necessarily trusted, improving and ensuring resilience and security guarantees against Byzantine faults and at-tacks. The generic approach of the TSKY system model and its implemented services are evaluated in the context of a Trusted Email Repository System (TSKY-TMS System). The TSKY-TMS system is a prototype that uses the base TSKY middleware services to store mailboxes and email Messages in a cloud-of-clouds

Anonymous network access using the digital marketplace

With increasing usage of mobile telephony, and the trend towards additional mobile Internet usage, privacy and anonymity become more and more important. Previously-published anonymous communication schemes aim to obscure their users' network addresses, because real-world identity can be easily be derived from this information. We propose modifications to a novel call-management architecture, the digital marketplace, which will break this link, therefore enabling truly anonymous network access

Private Handshakes

Private handshaking allows pairs of users to determine which (secret) groups they are both a member of. Group membership is kept secret to everybody else. Private handshaking is a more private form of secret handshaking, because it does not allow the group administrator to trace users. We extend the original definition of a handshaking protocol to allow and test for membership of multiple groups simultaneously. We present simple and efficient protocols for both the single group and multiple group membership case. Private handshaking is a useful tool for mutual authentication, demanded by many pervasive applications (including RFID) for privacy. Our implementations are efficient enough to support such usually resource constrained scenarios