YD
Y. Durmus
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1
The devices surrounding us become smarter and can autonomously form a network without requiring our intervention. However, our needs can be even better accommodated when the networked devices cooperate and complement each other’s capabilities. One of the initial steps towards achieving a cooperative platform of smart devices is the discovery of resources and capabilities within the network. Today’s operational service discovery protocols carry simple text-based uniform resource identifiers that are not expressive enough. Machines cannot comprehend the meaning of a new service that is not in their knowledge base. In addition to being more expressive, service discovery protocols must compensate the diversity to improve cooperation between the devices that use different application protocols and operate on different communication interfaces. In this paper, we propose the Smart Discovery Protocol (SDP) which outperforms the operational service discovery protocols with three main features: (1) more expressive semantic representation of the services, (2) operating in the network layer to deal with diversity, and (3) unifying existing service discovery protocols. SDP represents services with ontologies as some recently proposed semantic service discovery protocols. It further enhances the success of semantic representations by creating a unified platform that can carry legacy discovery services. In this respect, the novelties of SDP are as follows: firstly, it operates in the network layer and consequently abstracts both the application layer and communication interfaces. Secondly, SDP unifies the legacy service discovery protocols by integrating their simple text-based service representations in one message. The underlying transport mechanism of SDP is designed as an add-on to the Neighbor Discovery Protocol (NDP) of the IPv6 standard. The metadata is carried in the payload of ICMPv6 packets. Simple text-based representations of other service discovery protocols are embedded in type-length-value options of NDP. Authenticity of the devices is ensured by the IPv6 Secure Neighbor Discovery protocol. Unlike previous semantic approaches on service discovery, we have implemented our protocol on real hardware. The results demonstrate the feasibility of carrying semantic representations of the services and integration of other service discovery protocols.
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The devices surrounding us become smarter and can autonomously form a network without requiring our intervention. However, our needs can be even better accommodated when the networked devices cooperate and complement each other’s capabilities. One of the initial steps towards achieving a cooperative platform of smart devices is the discovery of resources and capabilities within the network. Today’s operational service discovery protocols carry simple text-based uniform resource identifiers that are not expressive enough. Machines cannot comprehend the meaning of a new service that is not in their knowledge base. In addition to being more expressive, service discovery protocols must compensate the diversity to improve cooperation between the devices that use different application protocols and operate on different communication interfaces. In this paper, we propose the Smart Discovery Protocol (SDP) which outperforms the operational service discovery protocols with three main features: (1) more expressive semantic representation of the services, (2) operating in the network layer to deal with diversity, and (3) unifying existing service discovery protocols. SDP represents services with ontologies as some recently proposed semantic service discovery protocols. It further enhances the success of semantic representations by creating a unified platform that can carry legacy discovery services. In this respect, the novelties of SDP are as follows: firstly, it operates in the network layer and consequently abstracts both the application layer and communication interfaces. Secondly, SDP unifies the legacy service discovery protocols by integrating their simple text-based service representations in one message. The underlying transport mechanism of SDP is designed as an add-on to the Neighbor Discovery Protocol (NDP) of the IPv6 standard. The metadata is carried in the payload of ICMPv6 packets. Simple text-based representations of other service discovery protocols are embedded in type-length-value options of NDP. Authenticity of the devices is ensured by the IPv6 Secure Neighbor Discovery protocol. Unlike previous semantic approaches on service discovery, we have implemented our protocol on real hardware. The results demonstrate the feasibility of carrying semantic representations of the services and integration of other service discovery protocols.
Cooperation is the foundation of wireless ad hoc networks with nodes forwarding their neighbors' packets for the common good. However, energy and bandwidth constraints combined with selfish behaviour lead to collapsed networks where all nodes defect. Researchers have tried to incentivize or enforce the nodes for cooperation in various ways. However, these techniques do not consider the heterogeneous networks in which a diverse set of nodes with different cognitive capabilities exist. Furthermore, in ad hoc networks identity is a fuzzy concept. It is easy to forge multiple identities and hide defective behaviour. Moreover, the nature of the wireless medium is always ambiguous due to collisions, interference and asymmetric links. In all this uncertainty, having complete information about the intentions of the nodes and acting on it is not straightforward. Backed by evolutionary game theory and multi-agent systems research, we adapt and modify two meta strategies to embrace this uncertainty. These modified meta strategies, Win Stay Loose Shift and Stochastic Imitate Best Strategy, do not require strict identity information and only depend on nodes' own capabilities. Nodes monitor the traffic in their neighbourhood by using a two-hop overhearing method, and decide whether they should be cooperative or defective. We show that nodes are able to discover and use the best strategy in their locality and protect themselves against the exploitation by free riders who devise Sybil attacks by changing their identities.
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Cooperation is the foundation of wireless ad hoc networks with nodes forwarding their neighbors' packets for the common good. However, energy and bandwidth constraints combined with selfish behaviour lead to collapsed networks where all nodes defect. Researchers have tried to incentivize or enforce the nodes for cooperation in various ways. However, these techniques do not consider the heterogeneous networks in which a diverse set of nodes with different cognitive capabilities exist. Furthermore, in ad hoc networks identity is a fuzzy concept. It is easy to forge multiple identities and hide defective behaviour. Moreover, the nature of the wireless medium is always ambiguous due to collisions, interference and asymmetric links. In all this uncertainty, having complete information about the intentions of the nodes and acting on it is not straightforward. Backed by evolutionary game theory and multi-agent systems research, we adapt and modify two meta strategies to embrace this uncertainty. These modified meta strategies, Win Stay Loose Shift and Stochastic Imitate Best Strategy, do not require strict identity information and only depend on nodes' own capabilities. Nodes monitor the traffic in their neighbourhood by using a two-hop overhearing method, and decide whether they should be cooperative or defective. We show that nodes are able to discover and use the best strategy in their locality and protect themselves against the exploitation by free riders who devise Sybil attacks by changing their identities.
WiFi Authentication through Social Networks
A Decentralized and Context-Aware Approach
With the proliferation of WiFi-enabled devices, people expect to be able to use them everywhere, be it at work, while commuting, or when visiting friends. In the latter case, home owners are confronted with the burden of controlling the access to their WiFi router, and usually resort to simply sharing the password. Although convenient, this solution breaches basic security principles, and puts the burden on the friends who have to enter the password in each and every of their devices. The use of social networks, specifying the trust relations between people and devices, provides for a more secure and more friendly authentication mechanism. In this paper, we progress the state-of-the-art by abandoning the centralized solution to embed social networks in WiFi authentication; we introduce EAP-SocTLS, a decentralized approach for authentication and authorization of WiFi access points and other devices, exploiting the embedded trust relations. In particular, we address the (quadratic) search complexity when indirect trust relations, like the smartphone of a friend's kid, are involved. We show that the simple heuristic of limiting the search to friends and devices in physical proximity makes for a scalable solution. Our prototype implementation, which is based on WebID and EAP-TLS, uses WiFi probe requests to determine the pool of neighboring devices and was shown to reduce the search time from 1 minute for the naive policy down to 11 seconds in the case of granting access over an indirect friend.
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With the proliferation of WiFi-enabled devices, people expect to be able to use them everywhere, be it at work, while commuting, or when visiting friends. In the latter case, home owners are confronted with the burden of controlling the access to their WiFi router, and usually resort to simply sharing the password. Although convenient, this solution breaches basic security principles, and puts the burden on the friends who have to enter the password in each and every of their devices. The use of social networks, specifying the trust relations between people and devices, provides for a more secure and more friendly authentication mechanism. In this paper, we progress the state-of-the-art by abandoning the centralized solution to embed social networks in WiFi authentication; we introduce EAP-SocTLS, a decentralized approach for authentication and authorization of WiFi access points and other devices, exploiting the embedded trust relations. In particular, we address the (quadratic) search complexity when indirect trust relations, like the smartphone of a friend's kid, are involved. We show that the simple heuristic of limiting the search to friends and devices in physical proximity makes for a scalable solution. Our prototype implementation, which is based on WebID and EAP-TLS, uses WiFi probe requests to determine the pool of neighboring devices and was shown to reduce the search time from 1 minute for the naive policy down to 11 seconds in the case of granting access over an indirect friend.