This page contains a list of all my publications, in chronological order


To route or to secure: Tradeoffs in ICNs over MANETs

Hasanat Kazmi, Hasnain Lakhani, Ashish Gehani, Rashid Tahir, Fareed Zaffar

The 15th IEEE International Symposium on Network Computing and Applications

DOI: 10.1109/NCA.2016.7778643

Link to full text version


Information-Centric Networks (ICNs) operating over Mobile Ad hoc Networks (MANETs) are challenged by the node churn, evolving topologies, and limited resources of the underlying network. The complex interplay of publishers, subscribers, and brokers brings with it a corresponding set of security concerns, where precisely-defined trust boundaries are needed to guarantee the confidentiality and integrity of all data objects in the ecosystem. Building a practical framework that can service users efficiently requires understanding the motivations and actions of the participants. We explore several tradeoffs between efficiency and the security of data objects in such environments, using ICEMAN – a real-wold implementation of an ICN that operates on MANETs. Since our findings are based on an actual system, they have significant implications for building efficient ICNs that have security designed in at the outset (rather than added later when options may be limited). We empirically establish that there is a strong interplay between the need to have more specific information for efficient routing and the need to ensure trust and confidentiality in such a decentralized system.

Energy efficient, context-aware cache coding for mobile information-centric networks

Joshua Joy, Yu-Ting Yu, Mario Gerla, Ashish Gehani, Hasnain Lakhani, Minyoung Kim

Proceedings of the 10th ACM International Conference on Distributed and Event-based Systems

DOI: 10.1145/2933267.2940322

Link to full text version


In a mobile, intermittently connected information-centric network (ICN), users download files either from the original source or from caches assembled during previous downloads. Network coding has helped to increase download robustness and overcome "missing coupon" delays. Prior work has also shown that network coding depletes energy resources much faster than no coding. Our contribution here is to make coding more efficient, and to detect when it is not necessary, in order to prolong the life of mobile handhelds. In the network coding context, Cache Coding (i.e., coding performed only on fully cached files) can prevent pollution attacks without significantly reducing diversity and performance with respect to unrestricted code mixing. Cache Coding introduces the first important means to reduce energy consumption by avoiding the extremely processor-intensive homomorphic code used in conventional unrestricted mixing networks. Our second contribution is to detect when Cache Coding is not required and disable it to save precious energy. The proposed Context-Aware Cache Coding (CACC) toggles between using Cache Coding and no coding based on the current network context (e.g., mobility, error rates, file size, etc). Our CACC implementation on Android devices demonstrates that the new scheme improves upon network coding's file delivery rate while keeping energy consumption in check.


Optimized Rollback and Re-computation

Hasnain Lakhani, Rashid Tahir, Azeem Aqil, Fareed Zaffar, Dawood Tariq, Ashish Gehani

Hawaii International Conference on System Sciences

DOI: 10.1109/HICSS.2013.434

Link to full text version


Large data processing tasks can be effected using workflow management systems. When either the input data or the programs in the pipeline are modified, the workflow must be re-executed to ensure that the final output data is updated to reflect the changes. Since such re-computation can consume substantial resources, optimizing the system to avoid redundant computation is desirable. In the case of a workflow, the depen- dency relationships between files are specified at the outset and can be leveraged to track which programs need to be re-executed when particular files change. Current distributed systems cannot provide such functionality when no predefined workflows exist. In this paper, we present an architecture that provides functionality to produce both correct output as well as fast re-execution by leveraging the provenance of data to propagate changes along an implicit dependency graph. We explore the tradeoff between storage and availability by presenting a performance analysis of our rollback and re-execution scheme.


Decentralized Authorization and Privacy-Enhanced Routing for Information-Centric Networks

Mariana Raykova, Hasnain Lakhani, Hasanat Kazmi, Ashish Gehani

2015 Annual Computer Security Applications Conference

DOI: 10.1145/2818000.2818001

Link to full text version


As information-centric networks are deployed in increasingly diverse settings, there is a growing need to protect the privacy of participants. We describe the design, implementation, and evaluation of a security framework that achieves this. It ensures the integrity and confidentiality of published content, the associated descriptive metadata, and the interests of subscribers. Publishers can scope access to the content, as well as which nodes in the network can broker access to it. Subscribers can limit which nodes can see their interests. Scopes are defined as policies over attributes of the individual nodes. The system transparently realizes the policies with suitable cryptographic primitives. It supports deployment in hetero-geneous mobile ad hoc environments where trust may derive from multiple independent sources. Further, no external public key infrastructure is assumed. We also report on the overhead that the security adds in actual deployments on Android devices.

Evaluation of a Delay-Tolerant ICN Architecture

Hasnain Lakhani, Timothy McCarthy, Minyoung Kim, David E. Wilkins, Samuel Wood

Excellent Paper Award

The Seventh International Conference on Ubiquitous and Future Networks

DOI: 10.1109/ICUFN.2015.7182686

Link to full text version


Simulation/emulation is key for early testing, assess­ment, and scalability evaluation of networking solutions for mo­bile ad-hoc networks (MANETs). If the solution is highly config­urable - such as ENCODERS, SRI's delay-tolerant information­ centric networking (ICN) solution - this type of evaluation is crucial. For effective modeling of information flows, the test framework needs to: (1) allow repeatable execution of scenarios with different patterns of network traffic, operating in different mobility and network-usage contexts, (2) provide a rich simulated environment that can model virtually any network topology and mobility, with high-fidelity device models, and (3) support flexible large-scale simulation, with the option of using virtual machines that execute the same code that would be used on an actual device. We describe our evaluation framework and the results of using it to develop and evaluate ENCODERS.

A Classification Based Framework to Predict Viral Threads

Hashim Sharif, Saad Ismail, Shehroze Farooqi, Mohammad Taha Khan, Muhammad Ali Gulzar, Hasnain Lakhani, Fareed Zaffar, Ahmed Abbasi

The 19th Pacific Asia Conference on Information Systems

DOI: PACIS 2015 Proceedings

Link to full text version


Online social media allows consumers to engage with each other and to create, share, discuss and modify user-generated content in a highly interactive way. Social media platforms have therefore become critical for companies trying to gauge the pulse of consumers, help identify issues faster, receive immediate feedback on products and offering etc. An effective social media strategy therefore requires companies to mine large volumes of structured unstructured and semi-structured online textual data in order to gain insights into the underlying traits of the consumers and prevailing public opinion. These insights can provide opportunities for market research, protection of brand reputation and a mechanism to gauge user preferences in an attempt to maximize customer satisfaction and consumer-brand engagement. In this paper, we propose and evaluate a classification based framework to predict thread lengths in online discussion forums in order to identify potential topics that may of interest to a particular online community. We identify and evaluate several key features of viral social media conversations through extensive experiments conducted on health 2.0 datasets. We also present a pharmaceutical industry based case study to illustrate how well the viral thread topics relate to real world events.


Covert Channels in Online Rogue-like Games

Hasnain Lakhani, Fareed Zaffar

2014 IEEE International Conference on Communications

DOI: 10.1109/ICC.2014.6883411

Link to full text version


Covert channels allow two parties to exchange secret data in the presence of adversaries without disclosing the fact that there is any secret data in their communications. We propose and implement EEDGE, an improved method for steganography in mazes that builds upon the work done by Lee et al; and has a significantly higher embedding capacity. We apply EEDGE to the setting of online rogue-like games, which have randomly generated mazes as the levels for players; and show that this can be used to successfully create an efficient, error-free, high bit-rate covert channel.