MQTLS: Toward Secure MQTT Communication with an Untrusted Broker

The publisher-subscriber (pub/sub) paradigm is one of the promising communication models to meet the requirements such as interoperability and support of heterogeneity for the Internet-of-Things (IoT). Message Queueing Telemetry Transport (MQTT), one of the protocols based on the pub/sub model, is widely used in practice with public brokers by Eclipse Mosquitto or HiveMQ. A broker in the pub/sub model, however, is intrinsically a man-in-the-middle between clients (i.e., publishers and subscribers); thus, a broker can read and alter all the messages delivered from publishers to subscribers. Therefore, both publishers and subscribers should not exchange confidential messages via an untrusted broker or should use it in-between them at risk. We propose MQTLS, an MQTT-aware secure communication protocol among publishers, subscribers, and brokers, while restricting brokers not to read any messages from publishers, except topics that need for message delivery. The MQTLS protocol is secure, based on our novel security definition called clientto-broker-to-client (CBC) security semantics for the pub/sub model. Our OpenSSL-based MQTLS proof-of-concept shows that MQTLS increases the delay time at the initial setup due to asymmetric signature/verification. However the delay time becomes marginal - only 4.06% at the high-end device and 10.04% at the low-end device compared with the standard TLS protocol - after the key is distributed.N

Public internet routing registries (IRR) evolution

Internet Routing Registries(IRR) have been around for quite some time now[1] with the sole purpose of providing the place for service providers to store their administrative, routing policy information which can be used in case of BGP malicious/misconfiguration events. Are there any useful service providers policy data stored in IRR? What current limited research has able to answer is that “Quality ” of IRR databases is not known”. By “Quality ” we mean validity of Internet Number Resources e.g. IPv4, IPv6, AS Number registration, routing policy registration, etc by different network service providers in IRR. We have tried to answer this question by looking into the public IRR datasets of approximately last 4 years [2006-2010].We have found out that current IRR datasets has a lot to offer than its known/practiced i.e. IRR has approximately 50k full peering available. We are investigating how many peering are in harmony with what BGP is announcing and also which is currently published in well known topology datasets like UCLA IRL[25].As we believe that if accurate peering can be extracted from IRR than they can provide number of new links which are missing in Internet Topology datasets. It can also reduce the usage of active measurements which in itself is burden on the network. We are also designing BGP Security framework based on IRR which will more accurately perform origin AS authentication as well as inferring the complete policy(what is stored in IRR) of AS

Measurement and Analysis of BitTorrent Traffic in Mobile WiMAX Networks

Abstract—As mobile Internet environments are becoming dom-inant, how to revamp P2P operations for mobile hosts is gaining more and more attention. In this paper, we carry out empirical traffic measurement of BitTorrent service in various settings (static, bus and subway) in commercial WiMAX networks. To this end, we analyze the connectivity among peers, the down-load throughput/stability, and the signaling overhead of mobile WiMAX hosts in comparison to a wired (Ethernet) host. We find out the drawbacks of BitTorrent operations in mobile Internet are characterized by lower connection ratio, unstable connections amongst peers, and higher control message overhead. I

Unveiling the BitTorrent Performance in Mobile WiMAX Networks

Abstract. As mobile Internet environments are becoming widespread, how to revamp peer-to-peer (P2P) operations for mobile hosts is gaining more attention. In this paper, we carry out empirical measurement of BitTorrent users in a commercial WiMAX network. We investigate how handovers in WiMAX networks impact the BitTorrent performance, how BitTorrent peers perform from the aspects of connectivity, stability and capability, and how the BitTorrent protocol behaves depending on user mobility. We observe that the drawbacks of BitTorrent for mobile users are characterized by poor connectivity among peers, short download ses-sion times, small download throughput, negligible upload contributions, and high signaling overhead

DSS: Distributed SINR-based scheduling algorithm for multihop wireless networks

The problem of developing distributed scheduling algorithms for high throughput in multihop wireless networks has been extensively studied in recent years. The design of a distributed low-complexity scheduling algorithm becomes even more challenging when taking into account a physical interference model, which requires the SINR at a receiver to be checked when making scheduling decisions. To do so, we need to check whether a transmission failure is caused by interference due to simultaneous transmissions from distant nodes. In this paper, we propose a scheduling algorithm under a physical interference model, which is amenable to distributed implementation with 802.11 CSMA technologies. The proposed scheduling algorithm is shown to achieve throughput optimality. We present two variations of the algorithm to enhance the delay performance and to reduce the control overhead, respectively, while retaining throughput optimality.close0