A secret sharing scheme is a method to store information securely and reliably. Particularly, in threshold scheme, encoded into n shares, such that any set of at least t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> shares suffice decode the secret, most xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> <; reveal no about secret. Assuming each party holds share user wishes by receiving from parties; question we study how minimize...

This paper studies secure unicast communication over a network with uniform wiretap sets and shows that, when nodes can independently generate randomness, determining the secrecy capacity is at least as difficult k-unicast coding problem. In particular, we show that general problem be reduced to of finding corresponding single link capacities any one link. We propose low-complexity linear optimization-based achievable strategy involving global random keys generated anywhere in network, an...

This paper studies the communication efficiency of threshold secret sharing schemes. We construct a family Shamir's schemes with asymptotically optimal decoding bandwidth for arbitrary parameters. also both and repair The construction leads to regenerating codes allowing centralized multiple node failures small sub-packetization.

We propose secure RAID, i.e., low-complexity schemes to store information in a distributed manner that is resilient node failures and resistant eavesdropping. generalize the concept of systematic encoding RAID show have significant advantages efficiencies encoding, decoding random access. For practical high rate regime, we construct three XOR-based with optimal complexities, from EVENODD codes B codes, which are array widely used architecture. These optimally tolerate two eavesdropping...

This paper constructs WOM codes that combine rewriting and error correction for mitigating the reliability endurance problems in flash memory.We consider a model is of practical interest to applications where only second write uses codes. Our code construction based on binary erasure quantization with LDGM codes, message passing has potential share efficient hardware implementations LDPC practice. We show coding scheme achieves capacity model. Extensive simulations performance our compares...

When sensitive data is stored in the cloud, only way to ensure its secrecy by encrypting it before uploaded. The emerging multi-cloud model, which redundantly two or more independent clouds, provides an opportunity protect with secret-sharing schemes. Both data-protection approaches are considered computationally expensive, but recent advances reduce their costs considerably: (1) Hardware acceleration methods promise eliminate computational complexity of encryption, leave clients challenge...

We study secure RAID, i.e., low-complexity schemes to store information in a distributed manner that is resilient node failures and resistant eavesdropping. describe technique shorten the EVENODD scheme [6], which can optimally tolerate 2 eavesdropping nodes. The shortening allows us obtain of arbitrary lengths, important for practical application. also construct new RAID from STAR code. 3 nodes with optimal encoding/decoding random access complexity.

This paper reduces multiple-unicast network coding to single-unicast secure and error correction. Specifically, we present reductions that map an arbitrary instance a unicast in which at most one link is eavesdropped, or correction erroneous, such rate tuple achievable the if only corresponding instance, instance. Conversely, show eavesdropped can be reduced back In addition, capacity of general not (exactly) achievable.

This paper studies rateless network error correction codes for reliable multicast in the presence of adversarial errors. We present coding schemes two models, where source sends more redundancy over time, until decoding succeeds. The first model assumes there is a secret channel between and destination that adversaries cannot overhear. rate negligible compared to main network. In second share random secrets independent input information. amount information required sent. Both are capacity...

Wireless sensor network (WSN) is a typical kind of low-power and lossy network, in where ARQ (Automatic Repeat reQuest) schemes are often used to improve packets reliability. However, the related may incur significant load consume more energy. This paper proposes novel energy efficient protocol called ARQ+, which uses nearest-first scheme NAK aggregation reduce amount transmission hops packets. Consequently, consumption significantly decreased. Theoretical analyses ARQ+ on consumption,...

A secret sharing scheme is a method to store information securely and reliably. Particularly, in threshold scheme, encoded into $n$ shares, such that any set of at least $t_1$ shares suffice decode the secret, most $t_2 < t_1$ reveal no about secret. Assuming each party holds share user wishes by receiving from parties; question we study how minimize amount communication between parties. We show necessary communication, termed "decoding bandwidth", decreases as number parties participate...

We consider the problem of characterizing network capacity in presence adversarial errors on links,focusing particular effect low-capacity feedback links cross cuts.

Consider the problem of reliable multicast over a network in presence adversarial errors. In contrast to traditional error correction codes designed for given capacity and number errors, we study an arguably more realistic setting that prior knowledge on adversary parameters is not available. For this propose efficient throughput-optimal schemes, provided source terminals share randomness secret form adversary. We discuss application cryptographic pseudorandom generators efficiently produce...

We show that solving a multiple-unicast network coding problem can be reduced to single-unicast error correction problem, where an adversary may jam at most single edge in the network. Specifically, we present efficient reduction maps instance while preserving feasibility. The holds for both zero probability of model and vanishing model. Previous reductions are restricted zero-error case. As application reduction, constructive example showing capacity not achievable, result separate interest.

This paper studies the problem of repairing secret sharing schemes, i.e., schemes that encode a message into $n$ shares, assigned to nodes, so any $n-r$ nodes can decode but colluding $z$ cannot infer information about message. In event node failures shares held by failed are lost, system needs be repaired reconstructing and reassigning lost (or replacement) nodes. achieved trivially trustworthy third-party receives available recompute reassign shares. The interesting question, studied in...

We consider the problem of secure communication over a network in presence wiretappers. give new cut-set bound on secrecy capacity which takes into account contribution both forward and backward edges crossing cut, connectivity between their endpoints rest network. show is tight class networks, demonstrates that it not possible to find tighter by considering only connectivity.

We study the problem of communicating over a single-source single-terminal network in presence an adversary that may jam single link network. If any one edges can be jammed, capacity such networks is well understood and follows directly from connection between minimum cut maximum flow networks. In this work we consider which some cannot show determining communication at least as hard solving multiple-unicast coding for error-free case. The latter long standing open problem.

In this paper, we present a novel approach to identify Tor hidden service access activity with key sequences under Obfs4 scenario. By calculating the cell signals occurred during process, get start index and window size of TCP package sequence traffic. order verify effectiveness method, perform comprehensive analysis nine scenarios different transmission model. We find through experimental results that there is window, which has great contribution identifying Only use as input, can achieve...

This paper shows determining the secrecy capacity of a unicast network with uniform wiretap sets is at least as difficult k-unicast problem. In particular, we show that general problem can be reduced to finding corresponding single link capacities and one arbitrary link.

We study the problem of communicating over a single-source single-terminal network in presence an adversary that may jam single link network. If any one edges can be jammed, capacity such networks is well understood and follows directly from connection between minimum cut maximum flow single- terminal networks. In this work we consider which some cannot show determining communication at least as hard solving multiple-unicast coding for error-free case. The latter long standing open problem.

We show that solving a multiple-unicast network coding problem can be reduced to single-unicast error correction problem, where an adversary may jam at most single edge in the network. Specifically, we present efficient reduction maps instance while preserving feasibility. The holds for both zero probability of model and vanishing model. Previous reductions are restricted zero-error case. As application reduction, constructive example showing capacity not achievable, result separate interest.

This paper considers rateless network error correction codes for reliable multicast in the presence of adversarial errors. Most existing are designed a given capacity and maximum number errors known priori to encoder decoder. However, certain practical settings it may be necessary operate without such knowledge. We present coding schemes two models, where source sends more redundancy over time, until decoding succeeds. The first model assumes there is secret channel between destination that...