Ryota Matsumoto

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This paper shows that the BB84 protocol with random privacy amplification is secure with a higher key rate than Mayers' estimate with the same error rate. Consequently, the tolerable error rate of this protocol is increased from 7.5% to 11%. We also extend this method to the case of estimating error rates separately in each basis, which enables us to(More)
We propose an information reconciliation protocol that uses two-way classical communication. In the case of the BB84 protocol and the six-state protocol, the key rates of the quantum key distribution (QKD) protocols that use our proposed information reconciliation protocol are higher than previously known protocols for wide range of error rates. We also(More)
In this paper, we describe the results of an empirical study on two spam detection methods: support vector machines (SVMs) and naive Bayes classifier (NBC). To conduct the study, we implement the NBC and choose to use the SVM/sup light/, an application of SVMs developed by Thorsten Joachims. The NBC and the linear SVMs with different C parameters are(More)
We propose Dijkstrapsilas algorithm with bounded list size after QR decomposition for decreasing the computational complexity of near maximum-likelihood (ML) detection of signals over multiple-input-multiple-output (MIMO) channels. After that, we compare the performances of proposed algorithm, QR decomposition M-algorithm (QRM-MLD), and its improvement.(More)
We consider the problem of secret key agreement in Gaussian Maurerpsilas Model. In Gaussian Maurerpsilas model, legitimate receivers, Alice and Bob, and a wire-tapper, Eve, receive signals randomly generated by a satellite through three independent memoryless Gaussian channels respectively. Then Alice and Bob generate a common secret key from their received(More)
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