A Semantic Hierarchy for Erasure Policies

We consider the problem of logical data erasure, contrasting with physical erasure in the same way that end-to-end information flow control contrasts with access control. We present a semantic hierarchy for erasure policies, using a possibilistic knowledge-based semantics to define policy satisfaction such that there is an intuitively clear upper bound on what information an erasure policy permits to be retained. Our hierarchy allows a rich class of erasure policies to be expressed, taking account of the power of the attacker, how much information may be retained, and under what conditions it may be retained. While our main aim is to specify erasure policies, the semantic framework allows quite general information-flow policies to be formulated for a variety of semantic notions of secrecy.Comment: 18 pages, ICISS 201

Faulty Successive Cancellation Decoding of Polar Codes for the Binary Erasure Channel

We study faulty successive cancellation decoding of polar codes for the binary erasure channel. To this end, we introduce a simple erasure-based fault model and we show that, under this model, polarization does not happen, meaning that fully reliable communication is not possible at any rate. Moreover, we provide numerical results for the frame erasure rate and bit erasure rate and we study an unequal error protection scheme that can significantly improve the performance of the faulty successive cancellation decoder with negligible overhead.Comment: As presented at ISITA 201

Information Erasure and Recover in Quantum Memory

We show that information in quantum memory can be erased and recovered perfectly if it is necessary. That the final states of environment are completely determined by the initial states of the system allows that an easure operation can be realized by a swap operation between system and an ancilla. Therefore, the erased information can be recoverd. When there is an irreversible process, e.g. an irreversible operation or a decoherence process, in the erasure process, the information would be erased perpetually. We present that quantum erasure will also give heat dissipation in environment. And a classical limit of quantum erasure is given which coincides with Landauer's erasure principle.Comment: PACS: 0365.Bz. 03.67.Hk;3page

Systematic MDS erasure codes based on vandermonde matrices

An increasing number of applications in computer communications uses erasure codes to cope with packet losses. Systematic maximum-distance separable (MDS) codes are often the best adapted codes. This letter introduces new systematic MDS erasure codes constructed from two Vandermonde matrices. These codes have lower coding and decoding complexities than the others systematic MDS erasure codes

On the Oblivious Transfer Capacity of the Degraded Wiretapped Binary Erasure Channel

We study oblivious transfer (OT) between Alice and Bob in the presence of an eavesdropper Eve over a degraded wiretapped binary erasure channel from Alice to Bob and Eve. In addition to the privacy goals of oblivious transfer between Alice and Bob, we require privacy of Alice and Bob's private data from Eve. In previous work we derived the OT capacity (in the honest-but-curious model) of the wiretapped binary independent erasure channel where the erasure processes of Bob and Eve are independent. Here we derive a lower bound on the OT capacity in the same secrecy model when the wiretapped binary erasure channel is degraded in favour of Bob.Comment: To be presented at the IEEE International Symposium on Information Theory (ISIT 2015), Hong Kon

Strong Secrecy on the Binary Erasure Wiretap Channel Using Large-Girth LDPC Codes

For an arbitrary degree distribution pair (DDP), we construct a sequence of low-density parity-check (LDPC) code ensembles with girth growing logarithmically in block-length using Ramanujan graphs. When the DDP has minimum left degree at least three, we show using density evolution analysis that the expected bit-error probability of these ensembles, when passed through a binary erasure channel with erasure probability $\epsilon$, decays as $\mathcal{O}(\exp(-c_1 n^{c_2}))$ with the block-length $n$ for positive constants $c_1$ and $c_2$, as long as $\epsilon$ is lesser than the erasure threshold $\epsilon_\mathrm{th}$ of the DDP. This guarantees that the coset coding scheme using the dual sequence provides strong secrecy over the binary erasure wiretap channel for erasure probabilities greater than $1 - \epsilon_\mathrm{th}$.Comment: 11 pages, 4 figures. Submitted to the IEEE Transactions on Information Forensics and Securit