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This paper considers polar coding for asymmetric settings, that is, channel coding for asymmetric channels and lossy source coding for nonuniform sources and/or asymmetric distortion measures. The difficulty for asymmetric settings comes from the fact that the optimal symbol distributions of codewords are not always uniform. It is known that such nonuniform(More)
permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Abstract—Rate-distortion theory is considered for the Shannon cipher system (SCS). The(More)
permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Abstract-Using the Viterbi decoding algorithm with repeat request for convolutional(More)
permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Abstract-Source coding problems are treated for Shannon's cipher system with correlated(More)
Private information retrieval scheme for coded data storage is considered in this paper. We focus on the case where the size of each data record is large and hence only the download cost (but not the upload cost for transmitting retrieval queries) is of interest. We prove that the tradeoff between storage cost and retrieval/download cost depends on the(More)
SUMMARY In a network with capacity h for multicast, information X h = (X 1 , X 2 , · · · , X h) can be transmitted from a source node to sink nodes without error by a linear network code. Furthermore, secret information S r = (S 1 , S 2 , · · · , S r) can be transmitted securely against wiretappers by k-secure network coding for k ≤ h−r. In this case, no(More)
Quantum secret sharing schemes encrypting a quantum state into a multipartite entangled state are treated. The lower bound on the dimension of each share given by Gottesman ͓Phys. Rev. A 61, 042311 ͑2000͔͒ is revisited based on a relation between the reversibility of quantum operations and the Holevo information. We also propose a threshold ramp quantum(More)
It is known that for any general access structure, a secret sharing scheme (SSS) can be constructed from an (m, m)-threshold scheme by using the so-called cumulative map or from a (t, m)-threshold SSS by a modified cumulative map. However, such constructed SSSs are not efficient generally. In this paper, we propose a new method to construct a SSS from a (t,(More)