465 research outputs found
Preventing DDoS using Bloom Filter: A Survey
Distributed Denial-of-Service (DDoS) is a menace for service provider and
prominent issue in network security. Defeating or defending the DDoS is a prime
challenge. DDoS make a service unavailable for a certain time. This phenomenon
harms the service providers, and hence, loss of business revenue. Therefore,
DDoS is a grand challenge to defeat. There are numerous mechanism to defend
DDoS, however, this paper surveys the deployment of Bloom Filter in defending a
DDoS attack. The Bloom Filter is a probabilistic data structure for membership
query that returns either true or false. Bloom Filter uses tiny memory to store
information of large data. Therefore, packet information is stored in Bloom
Filter to defend and defeat DDoS. This paper presents a survey on DDoS
defending technique using Bloom Filter.Comment: 9 pages, 1 figure. This article is accepted for publication in EAI
Endorsed Transactions on Scalable Information System
Exploratory study to explore the role of ICT in the process of knowledge management in an Indian business environment
In the 21st century and the emergence of a digital economy, knowledge and the knowledge base economy are rapidly growing. To effectively be able to understand the processes involved in the creating, managing and sharing of knowledge management in the business environment is critical to the success of an organization. This study builds on the previous research of the authors on the enablers of knowledge management by identifying the relationship between the enablers of knowledge management and the role played by information communication technologies (ICT) and ICT infrastructure in a business setting. This paper provides the findings of a survey collected from the four major Indian cities (Chennai, Coimbatore, Madurai and Villupuram) regarding their views and opinions about the enablers of knowledge management in business setting. A total of 80 organizations participated in the study with 100 participants in each city. The results show that ICT and ICT infrastructure can play a critical role in the creating, managing and sharing of knowledge in an Indian business environment
Contributions to the privacy provisioning for federated identity management platforms
Identity information, personal data and user’s profiles are key assets for organizations
and companies by becoming the use of identity management (IdM) infrastructures a prerequisite
for most companies, since IdM systems allow them to perform their business
transactions by sharing information and customizing services for several purposes in more
efficient and effective ways.
Due to the importance of the identity management paradigm, a lot of work has been done
so far resulting in a set of standards and specifications. According to them, under the
umbrella of the IdM paradigm a person’s digital identity can be shared, linked and reused
across different domains by allowing users simple session management, etc. In this way,
users’ information is widely collected and distributed to offer new added value services
and to enhance availability. Whereas these new services have a positive impact on users’
life, they also bring privacy problems.
To manage users’ personal data, while protecting their privacy, IdM systems are the ideal
target where to deploy privacy solutions, since they handle users’ attribute exchange.
Nevertheless, current IdM models and specifications do not sufficiently address comprehensive
privacy mechanisms or guidelines, which enable users to better control over the
use, divulging and revocation of their online identities. These are essential aspects, specially
in sensitive environments where incorrect and unsecured management of user’s data
may lead to attacks, privacy breaches, identity misuse or frauds.
Nowadays there are several approaches to IdM that have benefits and shortcomings, from
the privacy perspective.
In this thesis, the main goal is contributing to the privacy provisioning for federated
identity management platforms. And for this purpose, we propose a generic architecture
that extends current federation IdM systems. We have mainly focused our contributions
on health care environments, given their particularly sensitive nature. The two main
pillars of the proposed architecture, are the introduction of a selective privacy-enhanced
user profile management model and flexibility in revocation consent by incorporating an
event-based hybrid IdM approach, which enables to replace time constraints and explicit
revocation by activating and deactivating authorization rights according to events. The
combination of both models enables to deal with both online and offline scenarios, as well
as to empower the user role, by letting her to bring together identity information from
different sources.
Regarding user’s consent revocation, we propose an implicit revocation consent mechanism
based on events, that empowers a new concept, the sleepyhead credentials, which
is issued only once and would be used any time. Moreover, we integrate this concept
in IdM systems supporting a delegation protocol and we contribute with the definition
of mathematical model to determine event arrivals to the IdM system and how they are
managed to the corresponding entities, as well as its integration with the most widely
deployed specification, i.e., Security Assertion Markup Language (SAML).
In regard to user profile management, we define a privacy-awareness user profile management
model to provide efficient selective information disclosure. With this contribution a
service provider would be able to accesses the specific personal information without being
able to inspect any other details and keeping user control of her data by controlling
who can access. The structure that we consider for the user profile storage is based on
extensions of Merkle trees allowing for hash combining that would minimize the need of
individual verification of elements along a path. An algorithm for sorting the tree as we
envision frequently accessed attributes to be closer to the root (minimizing the access’
time) is also provided.
Formal validation of the above mentioned ideas has been carried out through simulations
and the development of prototypes. Besides, dissemination activities were performed in
projects, journals and conferences.Programa Oficial de Doctorado en IngenierĂa TelemáticaPresidente: MarĂa Celeste Campo Vázquez.- Secretario: MarĂa Francisca Hinarejos Campos.- Vocal: Ă“scar Esparza MartĂ
SecSip: A Stateful Firewall for SIP-based Networks
SIP-based networks are becoming the de-facto standard for voice, video and
instant messaging services. Being exposed to many threats while playing an
major role in the operation of essential services, the need for dedicated
security management approaches is rapidly increasing. In this paper we present
an original security management approach based on a specific vulnerability
aware SIP stateful firewall. Through known attack descriptions, we illustrate
the power of the configuration language of the firewall which uses the
capability to specify stateful objects that track data from multiple SIP
elements within their lifetime. We demonstrate through measurements on a real
implementation of the firewall its efficiency and performance
Key distribution technique for IPTV services with support for admission control and user defined groups
Tese de doutoramento. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 200
The enablers and implementation model for mobile KMS in Australian healthcare
In this research project, the enablers in implementing mobile KMS in Australian regional healthcare will be investigated, and a validated framework and guidelines to assist healthcare in implementing mobile KMS will also be proposed with both qualitative and quantitative approaches. The outcomes for this study are expected to improve the understanding the enabling factors in implementing mobile KMS in Australian healthcare, as well as provide better guidelines for this process
Security in peer-to-peer multimedia communications
Le architetture peer-to-peer (p2p) sono diventate molto popolari negli ultimi anni in conseguenza della grande varietĂ di servizi che esse possono fornire. Nate principalmente per l'utilizzo come semplice metodo scalabile e decentralizzato per scambiarsi file, sono adesso diventate molto popolari anche per una gran quantitĂ di altri servizi, sfruttando la possibilitĂ di condividere tra peer la banda, la potenza computazionale, la capacitĂ di memorizzazione ed altre risorse.
Tra i possibili usi per cui una tale architettura può essere sfruttata, un campo emergente è lo studio dell’applicazione di tecnologie p2p a comunicazioni VoIP in modo da superare alcuni dei problemi di cui soffrono correntemente le piattaforme centralizzate basate su SIP.
Sfortunatamente, i problemi di sicurezza delle reti p2p sono ancora un campo di studio aperto, sia per il recente sviluppo di una tale piattaforma, sia per i rischi intrinseci di un ambiente distribuito stesso.
Questa tesi ha lo scopo di studiare i problemi di sicurezza e le possibili soluzioni in modo da garantire una comunicazione sicura p2p. La ricerca è stata condotta in due direzioni:
sicurezza a livello di routing e sicurezza a livello applicativo.
Questi rappresentano I due possibili step di uno scenario di comunicazione: prima di tutto si deve trovare in modo sicuro la posizione di chi si vuole chiamare (che può essere memorizzata in una rete p2p stessa), e questo è un problema di lookup sicuro; in un secondo momento bisogna assicurarsi che la persona con cui si sta andando a parlare è veramente chi si voleva e che la comunicazione stessa sia confidenziale e non possa essere modificata; questi sono problemi di autenticazione e confidenzialità .
Per quanto riguarda il primo punto, si sono studiati molti possibili attacchi a reti p2p strutturate e non strutturate, concentrandosi particolarmente sul Sybil attack da cui molti altri attacchi possono derivare.
Dopo un analisi delle possibili contromisure presentate negli anni, ci siamo focalizzati sull’algoritmo DHT Kademlia, uno dei più usati nel mondo, studiando tramite simulazioni la degradazione delle performance in presenza di nodi malevoli. Si sono inoltre studiate contromisure basate su fiducia e reputazione e si è cercato di applicarle ad una rete Kademlia operante in un ambiente con un numero crescente di nodi malevoli.
Per quanto riguarda il secondo punto, come prima cosa abbiamo studiato gli attuali key agreement protocol, focalizzandoci sul numero di messaggi scambiati e cercando di trovare possibili punti deboli persino in protocolli ed algoritmi largamente utilizzati. In un secondo tempo si è proposto un nuovo key agreement protocol basato su MIKEY e ZRTP che li integra nella procedura standard di INVITE di SIP. E’ stata inoltre fatta un’analisi del protocollo proposto. Su queste basi, si è andati oltre, aggiungendo anche metodi di autenticazione basati sui certificati ed un modo per gestire in maniera p2p certificati e firme. Infine, si è anche pensato ad un’architettura dove i certificati sono memorizzati in una rete p2p stessa tramite l’utilizzo di DHT.Peer-to-peer (P2P) architectures became very popular in the last years as a consequence of the great variety of services they can provide. When they were born, they were mainly deployed as a simple, decentralized and scalable way to exchange files, but they have now become very popular also for a lot of different services, exploiting the possibility of sharing bandwidth, computing power, storage capacity and other resources between peers.
Among the possible uses such an architecture can be deployed for, an emerging field of study is the application of P2P technologies to VoIP communication scenarios in order to overcome some of the current issues centralized SIP-based platforms suffer of.
Unfortunately, security issues in P2P networks are still an open field of investigation both because of the recent development of such a platform and for the inherent risks of a distributed environment itself.
This thesis is meant to investigate the security issues and the possible solutions in order to setup a secure P2P communication. The research was conducted into two directions:
- Security issues at routing level;
- Security issues at application level.
They represent the two steps of a possible communication scenario: first of all one must find in a secure way the location of the callee (maybe stored in a peer-to-peer network), this is a problem of secure lookup; then one must ensure that the person he is going to talk with is really who he wanted and that the communication itself is secret and cannot be tampered, these are problems of authentication and confidentiality.
As regards the first point, we studied several possible attacks to structured and unstructured peer-to-peer networks particularly focalizing onto the disruptive Sybil attack from which many other attack can be derived.
After an analysis of the possible countermeasures presented over the years, we focalized onto the Kademlia algorithm, one of the most used in the world, studying through simulations the degradation of performances in presence of malicious nodes.
We also studied trust and reputation countermeasures and tried to apply them to a Kademlia-based network operating in an environment where there is a growing number of malicious nodes.
For the second point, first of all we studied current key agreement protocols focusing on the number of messages and trying to find out possible drawbacks even in widely accepted protocols and algorithms. In a second time we proposed a new key agreement protocol based upon MIKEY and ZRTP integrating them into the standard SIP invite procedure. An analysis of the proposed protocol is also provided. On this basis we got further, adding also certificate-based authentication to our model and a way to manage in a P2P way certificates and signatures. Finally we also provided an architecture where certificates are stored in a P2P network itself with the use of a DHT
Security in peer-to-peer communication systems
P2PSIP (Peer-to-Peer Session Initiation Protocol) is a protocol developed by the IETF (Internet Engineering Task Force) for the establishment, completion and modiÂżcation of communication sessions that emerges as a complement to SIP (Session Initiation Protocol) in environments where the original SIP protocol may fail for technical, Âżnancial, security, or social reasons. In order to do so, P2PSIP systems replace all the architecture of servers of the original SIP systems used for the registration and location of users, by a structured P2P network that distributes these functions among all the user agents that are part of the system. This new architecture, as with any emerging system, presents a completely new security problematic which analysis, subject of this thesis, is of crucial importance for its secure development and future standardization.
Starting with a study of the state of the art in network security and continuing with more speciÂżc systems such as SIP and P2P, we identify the most important security services within the architecture of a P2PSIP communication system: access control, bootstrap, routing, storage and communication. Once the security services have been identiÂżed, we conduct an analysis of the attacks that can aÂżect each of them, as well as a study of the existing countermeasures that can be used to prevent or mitigate these attacks. Based on the presented attacks and the weaknesses found in the existing measures to prevent them, we design speciÂżc solutions to improve the security of P2PSIP communication systems. To this end, we focus on the service that stands as the cornerstone of P2PSIP communication systemsÂż security: access control. Among the new designed solutions stand out: a certiÂżcation model based on the segregation of the identity of users and nodes, a model for secure access control for on-the-Âży P2PSIP systems
and an authorization framework for P2PSIP systems built on the recently published Internet Attribute CertiÂżcate ProÂżle for Authorization.
Finally, based on the existing measures and the new solutions designed, we deÂżne a set of security recommendations that should be considered for the design, implementation and maintenance of P2PSIP communication systems.Postprint (published version
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