Joao Girao

CDA: concealed data aggregation for reverse multicast traffic in wireless sensor networks

End-to-end encryption for wireless sensor networks is a challenging problem. To save the overall energy resources of the network, it is agreed that sensed data need to be consolidated and aggregated on their way to the final destination. We present an approach that (1) conceals sensed data end-to-end, by (2) still providing efficient in-network data aggregation. The aggregating intermediate nodes are not required to operate on the sensed plaintext data. We apply a particular class of encryption transformation and exemplarily discuss the approach on the basis of two aggregation functions. We use actual implementation to show that the approach is feasible and flexible and frequently even more energy efficient than hop-by-hop encryption.

Identities in the Future Internet of Things

There are two problem areas of the current Internet to be solved in Future Internet scenarios—security and putting the user back in control despite the move to the Internet of things. With this in mind, we address problems associated with the diversifying of the Internet towards an Internet of things, and with increased ways to be reachable, whether the user wants it or not, in the digital world. The paper presents two approaches to cope with the problem: The Identinet and a concept designated by the digital shadow. The paper presents an architecture based on these concepts.

Public Key Based Cryptoschemes for Data Concealment in Wireless Sensor Networks

In-network data aggregation is a popular technique for reducing the energy consumption tied to data transmission in a multi-hop wireless sensor network. However, data aggregation in untrusted or even hostile environments becomes problematic when end-to-end privacy between sensors and the sink is desired. In this paper we revisit and investigate the applicability of additively homomorphic public-key encryption algorithms for certain classes of wireless sensor networks. Finally, we provide recommendations for selecting the most suitable public key schemes for different topologies and wireless sensor network scenarios.

TinyPEDS: Tiny persistent encrypted data storage in asynchronous wireless sensor networks

In wireless sensor networks there is a need to securely store monitored data in a distributed way whenever it is either not desired or simply not possible to transmit regional volatile information to an authorised recipient in real-time. In particular, for wireless sensor network applications with an asynchronous character, the wireless sensor network itself needs to store the monitored data. Since nodes may disappear over time, a replicated and read-protected, but yet space- and energy-efficient, data storage is mandatory. In this work we provide and analyse an approach for a tiny Persistent Encrypted Data Storage (tinyPEDS) of the environmental fingerprint for asynchronous wireless sensor networks. Even if parts of the network are exhausted, restoring rules ensure that, with a high probability, environmental information from past is still available.

Secure comparison of encrypted data in wireless sensor networks

End-to-end encryption schemes that support operations over ciphertext are of utmost importance for commercial private party wireless sensor network implementations to become meaningful and profitable. For wireless sensor networks, we demonstrated in our previous work that privacy homomorphisms, when used for this purpose, offer two striking advantages apart from end-to-end concealment of data and ability to operate on ciphertexts: flexibility by keyless aggregation and conservation and balancing of aggregator backbone energy. We offered proof of concept by applying a certain privacy homomorphism for sensor network applications that rely on the addition operation. But a large class of aggregator functions like median computation or finding maximum/minimum rely exclusively on comparison operations. Unfortunately, as shown by Rivest, et al., any privacy homomorphism is insecure even against ciphertext that only attacks if they support comparison operations. In this paper we show that a particular order preserving encryption scheme achieves the above mentioned energy benefits and flexibility when used to support comparison operations over encrypted texts for wireless sensor networks, while also managing to hide the plaintext distribution and being secure against ciphertext only attacks. The scheme is shown to have reasonable memory and computation overhead when applied for wireless sensor networks.

Non-Manipulable Aggregator Node Election Protocols for Wireless Sensor Networks

Aggregator nodes commonly have the ability to read, corrupt or disrupt the flow of information produced by a wireless sensor network (WSN). Despite this fact, existing aggregator node election schemes do not address an adversary that strives to influence the election process towards candidate nodes that it controls. We discuss the requirements that need to be fulfilled by a non-manipulable aggregator node election protocol. We conclude that these requirements can be satisfied by a distributed random number generator function in which no node is able to determine the output of the function. We provide and compare three protocols that instantiate such function.

Who Said That? Privacy at Link Layer

Wireless LAN and other radio broadcast technologies are now in full swing. However, the widespread usage of these technologies comes at the price of location privacy, be it by observing the communication patterns or the interface identifiers. Although a number of network level solutions have been proposed , this paper describes a novel approach to location privacy at the link layer level. We present a generic mechanism and then map it to a real protocol, IEEE 802.11. The work also provides an analysis of the protocol in terms of privacy and performance considerations.

Virtual Identity Framework for Telecom Infrastructures

Identity Management has so far been a field mainly applications and Web focused. This paper describes a novel approach to cross layer identity management that extends digital identities to the network, the virtual identity (VID) framework. The VID framework provides strong privacy to the user, while easily supporting personalization cross-service providers. While other identity management solutions are tailored to one specific application and/or protocol domain, the proposed framework extends the use of one’s digital identity to all aspects of the network and services architecture. It is also the first to consider legal constrains, such as ownership of data and legal intercept issues, in such a broad scope. One major aspect reported here is the relevance for operators.

Recognition in a low-power environment

This paper formally defines recognition as a new security principle closely related to authentication. Low-power sensor networks with no pre-deployment information require the less authoritative security of recognition. We give general properties of recognition protocols based on the method of key disclosure. We examine previously proposed low-power protocols according to the environment and security model presented. Finally, we give measurements from an implementation of a recognition protocol called zero common-knowledge and discuss how well this proof-of-concept satisfies the properties of the environment.

HIP location privacy framework

Privacy and security are key aspects in future network architectures. The Host Identity Protocol (HIP) is a new proposal which decouples identifiers from locators and may eventually replace conventional addressing and network transport. In this document we propose an architecture that provides location privacy, based on HIP. We further validate our work by implementation and support the feasibility of our protocol by experimentation.