| 1. |
- Bocharova, Irina, et al.
(författare)
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Fast exponentation in cryptography
- 1995
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Ingår i: Applied Algebra, Algebraic Algorithms and Error-Correcting Codes/Lecture notes in computer science. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 1611-3349 .- 0302-9743. - 3540601147 ; 948, s. 146-157
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Konferensbidrag (refereegranskat)abstract
- We consider the problem of minimizing the number of multiplications in computing f(x)=x n , where n is an integer and x is an element of any ring. We present new methods which reduce the average number of multiplications comparing with well-known methods, such as the binary method and the q-ary method. We do not compare our approach with algorithms based on addition chains since our approach is intended for cryptosystems with large exponent n and the complexity of constructing the optimal addition chain for such n is too high. We consider the binary representation for the number n and simplify exponentiation by applying ideas close to ideas exploited in data compression. Asymptotical efficiency of the new algorithms is estimated and numerical results are given.
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| 2. |
- Wessman, Matts-Ola, 1972, et al.
(författare)
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Performance of Coded Single-Band Carrier-Based DS-SS Systems on IEEE 802.15.3a UWB Channels
- 2005
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Ingår i: Proceedings IEEE International Conference on Ultra-Wideband, Zürich, Switzerland. - 078039397X ; , s. 152-157
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Konferensbidrag (refereegranskat)abstract
- A set of physical layer specifications is provided for a single-band system. The system fulfills the FCC regulations on UWB devices and the physical layer requirements from IEEE 802.15.3a. It gives reliable communication, i.e., a 90th-percentile PER equal to 8% for 1024 payload bytes, at 110 Mbps with a transmitter-receiver separation of up to 10 meters on the IEEE 802.15.3a channel model CM4. 205 Mbps at 6.7 meters on CM4 and 513 Mbps at 3.8 meters on CM2 are also achieved. The system uses the spectrum 3.1-4.9 GHz, a chip-spaced Rake combiner with 60 fingers, a sliding window channel estimator, and a sampling rate of 1540 Msamples/s.
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