We consider the MIMO wiretap channel, that is a broadcast channel where transmitter sends some confidential information to one user which legitimate receiver, while other an eavesdropper. Perfect secrecy achieved when and receiver can communicate at positive rate, insuring eavesdropper gets zero bits of information. In this paper, we compute perfect capacity multiple antenna number antennas arbitrary for both two receivers. Our technique involves careful study Sato-like upper bound via...

In this paper, we introduce the notion of perfect space-time block codes (STBCs). These have full-rate, full-diversity, nonvanishing constant minimum determinant for increasing spectral efficiency, uniform average transmitted energy per antenna and good shaping. We present algebraic constructions STBCs 2, 3, 4, 6 antennas

We consider the MIMO wiretap channel, that is a broadcast channel where transmitter sends some confidential information to one user which legitimate receiver, while other an eavesdropper. Perfect secrecy achieved when and receiver can communicate at positive rate, insuring eavesdropper gets zero bits of information. In this paper, we compute perfect capacity multiple antenna number antennas arbitrary for both two receivers. Our technique involves careful study Sato-like upper bound via...

Erasure codes provide a storage efficient alternative to replication based redundancy in (networked) systems. They however entail high communication overhead for maintenance, when some of the encoded fragments are lost and need be replenished. Such overheads arise from fundamental recreate (or keep separately) first copy whole object before any individual fragment can generated There has recently been intense interest explore alternatives, most prominent ones being regenerating (RGC)...

In this correspondence, we present various families of full diversity rotated Z/sup n/-lattice constellations based on algebraic number theory constructions. We are able to give closed-form expressions their minimum product distance using the corresponding properties.

Distributed storage systems need to store data redundantly in order provide some fault-tolerance and guarantee system reliability. Different coding techniques have been proposed the required redundancy more efficiently than traditional replication schemes. However, compared replication, are less efficient for repairing lost redundancy, as they require retrieval of larger amounts from subsets nodes. To mitigate these problems, several recent works presented locally repairable codes designed...

We consider the Gaussian wiretap channel, where two legitimate players Alice and Bob communicate over an additive white noise (AWGN) while Eve is eavesdropping, also through AWGN channel. propose a coding strategy based on lattice coset encoding. define secrecy gain as design criterion for codes, expressed in terms of theta series, which characterizes Eve's confusion function channel parameters. The studied even unimodular lattices, asymptotic analysis shows that it grows exponentially...

This tutorial reviews fundamental contributions to information security. An integrative viewpoint is taken that explains the security metrics, including secrecy, privacy, and others, methodology of information-theoretic approaches, along with arising system design principles, as well techniques enable designs be applied in real communication computing systems. The tutorial, while summarizing these contributions, argues for simultaneous pivotal role limits coding secure design.

Algebraic number theory is having an increasing impact in code design for many different coding applications, such as single antenna fading channels and more recently, MIMO systems.Extended work has been done on channels, algebraic lattice codes have proven to be effective tool.The general framework settled the last ten years explicit constructions based are now available.The aim of this provide both overview designs Rayleigh well a tutorial introduction theory.The basic facts mathematical...

We propose the notion of secrecy gain as a code design criterion for wiretap lattice codes to be used over an additive white Gaussian noise channel. Our analysis relies on error probabilites both legitimate user and eavesdropper. focus geometrical properties lattices, described by their theta series, characterize good codes.

The Bitcoin network is a complex that records anonymous financial transactions while encapsulating the relationships among its pseudonymous users. This paper proposes graph mining techniques to explore wallet addresses (pseudonyms for users) suspected be involved in given extortion racket, exploiting anonymity of collect and launder money. Starting around potential interest, neighborhood subgraphs are analyzed terms path length confluence detect suspicious flow other controlled by...

Multiple-input double-output (MIDO) codes are important in the near-future wireless communications, where portable end-user device is physically small and will typically contain at most two receive antennas. Especially tempting 4 x 2 channel due to its immediate applicability digital video broadcasting (DVB). Such channels optimally employ rate-two space-time (ST) consisting of (4 4) matrices. Unfortunately, such general very complex decode, hence setting forth a call for constructions with...

This paper studies the design of distributed space-time codes for use in wireless relay networks. Earlier work suggested that a suitable family can be obtained by using linear dispersion codes, provided basis matrices were unitary. In this we construct an explicit algebraic such where full diversity is proved. The construction uses cyclotomic field theory and yields are indeed Simulation results show have better performance than designed earlier ad hoc random methods, thus with less encoding...

Coding for the Gaussian Wiretap Channel can be done with nested lattices. The fine lattice must designed in same way as lattices used on regular while coarse one a whose theta series is minimized. We present criterion of design both and when Rayleigh fading wiretap channel.

Self-Repairing Codes (SRC) are codes designed to suit the need of coding for distributed networked storage: they not only allow stored data be recovered even in presence node failures, also provide a repair mechanism where as little two live nodes can contacted regenerate failed node. In this paper, we propose new instance self-repairing codes, based on constructions spreads coming from projective geometry. We study some their properties demonstrate suitability these storage.

We propose a lattice construction from totally real and CM fields, which naturally generalizes the Construction A of lattices $p$-ary codes obtained cyclotomic field $\mathbb{Q}(\zeta_p)$, $p$ prime, in turn contains so-called binary as particular case. focus on maximal subfield $\mathbb{Q}(\zeta_{p^r}+\zeta_{p}^{-r})$ $\mathbb{Q}(\zeta_{p^r})$, $r\geq 1$. Our has applications to coset encoding algebraic codes, we detail case block fading wiretap codes.

The Rankin constant $\gamma_{n,l}$ measures the largest volume of densest sublattice rank $l$ a lattice $\Lambda\in \RR^n$ over all such lattices $n$. Berg\'e-Martinet $\gamma'_{n,l}$ is variation that takes into account dual lattice. Exact values and bounds for both constants are mostly open in general. We consider case built from linear codes, look at on $\gamma'_{n,l}$. In particular, we revisit known results $n=3,4,5,8$ give lower upper cases $\gamma_{5,2},\gamma_{7,2}$...

Recent years have witnessed a slew of coding techniques custom designed for networked storage systems. Network inspired regenerating codes are the most prolifically studied among these new age centric codes. A lot effort has been invested in understanding fundamental achievable trade-offs and bandwidth usage to maintain redundancy presence different models failures, showcasing efficacy with respect traditional erasure techniques. For practical usability open adversarial environments, as is...