Publications de Mahdi Jafari Siavoshani

Non-coherent Network Coding: An Arbitrarily Varying Channel Approach

In this paper, we propose an "arbitrarily varying channel" (AVC) approach to study the capacity of non-coherent transmission in a network that employs randomized linear network coding. The network operation is modeled by a matrix channel over a finite fiel ...

Ieee2012

Subspace properties of network coding and their applications

Suhas Diggavi, Christina Fragouli, Mahdi Jafari Siavoshani

Systems that employ network coding for content distribution convey to the receivers linear combinations of the source packets. If we assume randomized network coding, during this process the network nodes collect random subspaces of the space spanned by th ...

2012

Multi-terminal Secrecy in a Linear Non-coherent Packetized Networks

Christina Fragouli, Mahdi Jafari Siavoshani

We consider a group of m+1 trusted nodes that aim to create a shared secret key K over a network in the presence of a passive eavesdropper, Eve. We assume a linear non-coherent network coding broadcast channel (over a ﬁnite ﬁeld F_q ) from one of the hones ...

2012

Network Coding : Theoretical Designs Directed to Applications

Mahdi Jafari Siavoshani

The demand for higher throughput and better efficiency are two important challenges for future communication networks. During the past decades, a lot of research studies have been devoted to investigating and proposing near optimal and efficient schemes an ...

EPFL2012

Group secret key agreement over state-dependent wireless broadcast channels

Suhas Diggavi, Christina Fragouli, Mahdi Jafari Siavoshani

We consider a group of m trusted nodes that aim to create a shared secret key K, using a state-dependent wireless broadcast channel that exists from one of the honest nodes to the rest of the nodes including a passive eavesdropper Eve. All of the trusted n ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2011

On the capacity of non-coherent network coding

Suhas Diggavi, Christina Fragouli, Soheil Mohajerzefreh, Mahdi Jafari Siavoshani

We consider the problem of multicasting information from a source to a set of receivers over a network where interme- diate network nodes perform randomized linear network coding operations on the source packets. We propose a channel model for the noncoher ...

2011

Erased Secrets: Practical Information-Theoretic Group Secrecy

Suhas Diggavi, Christina Fragouli, Mahdi Jafari Siavoshani, Aikaterini Argyraki, Uday Kiran Pulleti

We consider the scenario where a group of wireless nodes want to exchange a secret key, such that no eavesdropper can guess the key. Today, this can be achieved using publickey cryptography, e.g., the Diffie-Hellman or the RSA keyexchange algorithms. Howev ...

2010

Joint Identity-Message Coding for Sensor Networks

Lorenzo Keller, Suhas Diggavi, Christina Fragouli, Mahdi Jafari Siavoshani, Aikaterini Argyraki

In a significant class of sensor-network applications, the identities of the reporting sensors constitute the bulk of the communicated data, whereas the message itself can be as small as a single bit—for instance, in many cases, sensors are used to detect ...

Institute of Electrical and Electronics Engineers2010

Compressed network coding vectors

Lorenzo Keller, Christina Fragouli, Mahdi Jafari Siavoshani, Aikaterini Argyraki

In networks that employ network coding, two main approaches have been proposed in the literature to allow the receivers to recover the source information: (i) use of coding vectors, that keep track of the linear combinations the received packets contain, a ...

2009

Identity Aware Sensor Networks

Lorenzo Keller, Suhas Diggavi, Christina Fragouli, Mahdi Jafari Siavoshani, Aikaterini Argyraki

In a significant class of sensor-network applications, the identities of the reporting sensors constitute the bulk of the communicated data, whereas the message itself can be as small as a single bit---for instance, in many cases, sensors are used to detec ...

2009

On the capacity of multisource non-coherent network coding

Suhas Diggavi, Christina Fragouli, Soheil Mohajerzefreh, Mahdi Jafari Siavoshani

We consider multisource non-coherent network coding, where multiple sources send information to one or multiple receivers. We prove that this is equivalent to a ldquosubspacerdquo channel, that takes subspaces as inputs and outputs. We then show that the r ...

2009

On Locating Byzantine Attackers

Suhas Diggavi, Christina Fragouli, Mahdi Jafari Siavoshani

We examine networks that employ network coding, and are subject to Byzantine attacks. We consider systems where an appropriate network error correcting scheme is employed that is able to correct (up to a certain number of) Byzantine errors. Given this setu ...

2008

Noncoherent multi-source network coding

Suhas Diggavi, Christina Fragouli, Mahdi Jafari Siavoshani

We examine the problem of multiple sources transmitting information to one or more receivers that require the information from all the sources, over a network where the network nodes perform randomized network coding. We consider the noncoherent case, wher ...

2008

Bottleneck Discovery and Overlay Management in Network Coded Peer-to-Peer Systems

Suhas Diggavi, Christina Fragouli, Mahdi Jafari Siavoshani

The performance of peer-to-peer (P2P) networks depends critically on the good connectivity of the overlay topology. In this paper we study P2P networks for content distribution (such as Avalanche) that use randomized network coding techniques. The basic id ...

2007

Subspace properties of randomized network coding

Suhas Diggavi, Christina Fragouli, Mahdi Jafari Siavoshani

Randomized network coding has network nodes randomly combine and exchange linear combinations of the source packets. A header appended to the packet, called coding vector, specifies the exact linear combination that each packet carries. The main contributi ...

2007