993 research outputs found
Privacy protection for e-health systems by means of dynamic authentication and three-factor key agreement
During the past decade, the electronic healthcare (e-health) system has been evolved into a more patient-oriented service with smaller and smarter wireless devices. However, these convenient smart devices have limited computing capacity and memory size, which makes it harder to protect the user’s massive private data in the e-health system. Although some works have established a secure session key between the user and the medical server, the weaknesses still exist in preserving the anonymity with low energy consumption. Moreover, the misuse of biometric information in key agreement process may lead to privacy disclosure, which is irreparable. In this study, we design a dynamic privacy protection mechanism offering the biometric authentication at the server side whereas the exact value of the biometric template remains unknown to the server. And the user anonymity can be fully preserved during the authentication and key negotiation process because the messages transmitted with the proposed scheme are untraceable. Furthermore, the proposed scheme is proved to be semantic secure under the Real-or-Random Model. The performance analysis shows that the proposed scheme suits the e-health environment at the aspect of security and resource occupation
HMAKE: Legacy-Compliant Multi-factor Authenticated Key Exchange from Historical Data
In this paper, we introduce two lightweight historical data based multi-factor authenticated key exchange (HMAKE) protocols in the random oracle model. Our HMAKE protocols use a symmetric secret key, as their first authentication factor, together with their second authentication factor, historical data exchanged between the two parties in the past, and the third authentication factor, a set of secret tags associated with the historical data, to establish a secure communication channel between the client and the server.
A remarkable security feature of HMAKE is bounded historical tag leakage resilience, which means that (informally speaking) if a small portion of the secret tags is leaked to an adversary, it will not affect the security of one HMAKE protocol with an overwhelming probability. Our first HMAKE protocol can provide static bounded leakage resilience, meaning that the secret tags are leaked at the beginning of the security game. To enhance its security, our second HMAKE protocol makes use of our first protocol as a compiler to transform any passively secure two-message key exchange protocol to an actively secure HMAKE protocol with perfect forward secrecy, and therefore it can be secure even if the historical tags are compromised adaptively by an attacker.
In addition to the strong security properties we achieved, our protocols can potentially have great impacts in practice: they are efficient in computation, and they are compatible with legacy devices in cyber-physical systems
Identity Management and Authorization Infrastructure in Secure Mobile Access to Electronic Health Records
We live in an age of the mobile paradigm of anytime/anywhere access, as the mobile device
is the most ubiquitous device that people now hold. Due to their portability, availability, easy
of use, communication, access and sharing of information within various domains and areas of
our daily lives, the acceptance and adoption of these devices is still growing. However, due to
their potential and raising numbers, mobile devices are a growing target for attackers and, like
other technologies, mobile applications are still vulnerable.
Health information systems are composed with tools and software to collect, manage, analyze
and process medical information (such as electronic health records and personal health records).
Therefore, such systems can empower the performance and maintenance of health services,
promoting availability, readability, accessibility and data sharing of vital information about a
patients overall medical history, between geographic fragmented health services. Quick access
to information presents a great importance in the health sector, as it accelerates work processes,
resulting in better time utilization. Additionally, it may increase the quality of care.
However health information systems store and manage highly sensitive data, which raises serious
concerns regarding patients privacy and safety, and may explain the still increasing number
of malicious incidents reports within the health domain.
Data related to health information systems are highly sensitive and subject to severe legal
and regulatory restrictions, that aim to protect the individual rights and privacy of patients.
Along side with these legislations, security requirements must be analyzed and measures implemented.
Within the necessary security requirements to access health data, secure authentication,
identity management and access control are essential to provide adequate means to
protect data from unauthorized accesses. However, besides the use of simple authentication
models, traditional access control models are commonly based on predefined access policies
and roles, and are inflexible. This results in uniform access control decisions through people,
different type of devices, environments and situational conditions, and across enterprises, location
and time.
Although already existent models allow to ensure the needs of the health care systems, they still
lack components for dynamicity and privacy protection, which leads to not have desire levels
of security and to the patient not to have a full and easy control of his privacy. Within this
master thesis, after a deep research and review of the stat of art, was published a novel dynamic
access control model, Socio-Technical Risk-Adaptable Access Control modEl (SoTRAACE),
which can model the inherent differences and security requirements that are present in this
thesis. To do this, SoTRAACE aggregates attributes from various domains to help performing
a risk assessment at the moment of the request. The assessment of the risk factors identified
in this work is based in a Delphi Study. A set of security experts from various domains were
selected, to classify the impact in the risk assessment of each attribute that SoTRAACE aggregates.
SoTRAACE was integrated in an architecture with requirements well-founded, and based
in the best recommendations and standards (OWASP, NIST 800-53, NIST 800-57), as well based in
deep review of the state-of-art. The architecture is further targeted with the essential security
analysis and the threat model. As proof of concept, the proposed access control model was implemented within the user-centric
architecture, with two mobile prototypes for several types of accesses by patients and healthcare
professionals, as well the web servers that handles the access requests, authentication and
identity management.
The proof of concept shows that the model works as expected, with transparency, assuring privacy
and data control to the user without impact for user experience and interaction. It is clear
that the model can be extended to other industry domains, and new levels of risks or attributes
can be added because it is modular. The architecture also works as expected, assuring secure
authentication with multifactor, and secure data share/access based in SoTRAACE decisions.
The communication channel that SoTRAACE uses was also protected with a digital certificate.
At last, the architecture was tested within different Android versions, tested with static and
dynamic analysis and with tests with security tools.
Future work includes the integration of health data standards and evaluating the proposed system
by collecting users’ opinion after releasing the system to real world.Hoje em dia vivemos em um paradigma móvel de acesso em qualquer lugar/hora, sendo que
os dispositivos móveis são a tecnologia mais presente no dia a dia da sociedade. Devido à sua
portabilidade, disponibilidade, fácil manuseamento, poder de comunicação, acesso e partilha
de informação referentes a várias áreas e domínios das nossas vidas, a aceitação e integração
destes dispositivos é cada vez maior. No entanto, devido ao seu potencial e aumento do número
de utilizadores, os dispositivos móveis são cada vez mais alvos de ataques, e tal como outras
tecnologias, aplicações móveis continuam a ser vulneráveis.
Sistemas de informação de saúde são compostos por ferramentas e softwares que permitem
recolher, administrar, analisar e processar informação médica (tais como documentos de saúde
eletrónicos). Portanto, tais sistemas podem potencializar a performance e a manutenção dos
serviços de saúde, promovendo assim a disponibilidade, acessibilidade e a partilha de dados
vitais referentes ao registro médico geral dos pacientes, entre serviços e instituições que estão
geograficamente fragmentadas. O rápido acesso a informações médicas apresenta uma grande
importância para o setor da saúde, dado que acelera os processos de trabalho, resultando assim
numa melhor eficiência na utilização do tempo e recursos. Consequentemente haverá uma
melhor qualidade de tratamento. Porém os sistemas de informação de saúde armazenam e
manuseiam dados bastantes sensíveis, o que levanta sérias preocupações referentes à privacidade
e segurança do paciente. Assim se explica o aumento de incidentes maliciosos dentro do
domínio da saúde.
Os dados de saúde são altamente sensíveis e são sujeitos a severas leis e restrições regulamentares,
que pretendem assegurar a proteção dos direitos e privacidade dos pacientes, salvaguardando
os seus dados de saúde. Juntamente com estas legislações, requerimentos de segurança
devem ser analisados e medidas implementadas. Dentro dos requerimentos necessários
para aceder aos dados de saúde, uma autenticação segura, gestão de identidade e controlos de
acesso são essenciais para fornecer meios adequados para a proteção de dados contra acessos
não autorizados. No entanto, além do uso de modelos simples de autenticação, os modelos
tradicionais de controlo de acesso são normalmente baseados em políticas de acesso e cargos
pré-definidos, e são inflexíveis. Isto resulta em decisões de controlo de acesso uniformes para
diferentes pessoas, tipos de dispositivo, ambientes e condições situacionais, empresas, localizações
e diferentes alturas no tempo. Apesar dos modelos existentes permitirem assegurar
algumas necessidades dos sistemas de saúde, ainda há escassez de componentes para accesso
dinâmico e proteção de privacidade , o que resultam em níveis de segurança não satisfatórios e
em o paciente não ter controlo directo e total sobre a sua privacidade e documentos de saúde.
Dentro desta tese de mestrado, depois da investigação e revisão intensiva do estado da arte,
foi publicado um modelo inovador de controlo de acesso, chamado SoTRAACE, que molda as
diferenças de acesso inerentes e requerimentos de segurança presentes nesta tese. Para isto,
o SoTRAACE agrega atributos de vários ambientes e domínios que ajudam a executar uma avaliação
de riscos, no momento em que os dados são requisitados. A avaliação dos fatores de risco
identificados neste trabalho são baseados num estudo de Delphi. Um conjunto de peritos de
segurança de vários domínios industriais foram selecionados, para classificar o impacto de cada
atributo que o SoTRAACE agrega. O SoTRAACE foi integrado numa arquitectura para acesso a
dados médicos, com requerimentos bem fundados, baseados nas melhores normas e recomendações (OWASP, NIST 800-53, NIST 800-57), e em revisões intensivas do estado da arte. Esta
arquitectura é posteriormente alvo de uma análise de segurança e modelos de ataque.
Como prova deste conceito, o modelo de controlo de acesso proposto é implementado juntamente
com uma arquitetura focada no utilizador, com dois protótipos para aplicações móveis,
que providênciam vários tipos de acesso de pacientes e profissionais de saúde. A arquitetura é
constituída também por servidores web que tratam da gestão de dados, controlo de acesso e
autenticação e gestão de identidade. O resultado final mostra que o modelo funciona como esperado,
com transparência, assegurando a privacidade e o controlo de dados para o utilizador,
sem ter impacto na sua interação e experiência. Consequentemente este modelo pode-se extender
para outros setores industriais, e novos níveis de risco ou atributos podem ser adicionados
a este mesmo, por ser modular. A arquitetura também funciona como esperado, assegurando
uma autenticação segura com multi-fator, acesso e partilha de dados segura baseado em decisões
do SoTRAACE. O canal de comunicação que o SoTRAACE usa foi também protegido com
um certificado digital.
A arquitectura foi testada em diferentes versões de Android, e foi alvo de análise estática,
dinâmica e testes com ferramentas de segurança.
Para trabalho futuro está planeado a integração de normas de dados de saúde e a avaliação do
sistema proposto, através da recolha de opiniões de utilizadores no mundo real
Flexible Framework for Secret Handshakes (Multi-Party Anonymous and Un-observable Authentication)
In the society increasingly concerned with the erosion of privacy,
privacy-preserving techniques are becoming very important.
This motivates research in cryptographic techniques offering
built-in privacy.
A secret handshake is a protocol whereby participants establish
a secure, anonymous and unobservable communication channel only
if they are members of the same group. This type of ``private
authentication is a valuable tool in the arsenal of privacy-preserving
cryptographic techniques. Prior research focused on 2-party secret
handshakes with one-time credentials.
This paper breaks new ground on two accounts: (1) it shows how
to obtain secure and efficient secret handshakes with reusable
credentials, and (2) it represents the first treatment of group
(or {\em multi-party}) secret handshakes, thus providing a
natural extension to the secret handshake technology. An
interesting new issue encountered in multi-party secret handshakes
is the need to ensure that all parties are indeed distinct.
(This is a real challenge since the parties cannot expose their
identities.) We tackle this and other challenging issues in
constructing GCD -- a flexible framework for secret handshakes.
The proposed framework lends itself to many practical
instantiations and offers several novel and appealing features
such as self-distinction and strong anonymity with reusable
credentials. In addition to describing the motivation and
step-by-step construction of the framework, this paper provides
a thorough security analysis and illustrates two concrete
framework instantiations
ProvablySecure Authenticated Group Diffie-Hellman Key Exchange
Abstract: Authenticated key exchange protocols allow two participants A and B, communicating over a public network and each holding an authentication means, to exchange a shared secret value. Methods designed to deal with this cryptographic problem ensure A (resp. B) that no other participants aside from B (resp. A) can learn any information about the agreed value, and often also ensure A and B that their respective partner has actually computed this value. A natural extension to this cryptographic method is to consider a pool of participants exchanging a shared secret value and to provide a formal treatment for it. Starting from the famous 2-party Diffie-Hellman (DH) key exchange protocol, and from its authenticated variants, security experts have extended it to the multi-party setting for over a decade and completed a formal analysis in the framework of modern cryptography in the past few years. The present paper synthesizes this body of work on the provably-secure authenticated group DH key exchange. The present paper revisits and combines the full versions of the following four papers
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