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Space/Time Trade-Offs for Higher Radix Modular Multiplication Using Repeated Addition
February 1997 (vol. 46 no. 2)
pp. 139-141

Abstract—The value of using a higher radix for modular multiplication in the context of RSA is investigated. The main conclusion is that for algorithms which perform the multiplication via repeated addition, there is, broadly speaking, a direct trade-off between space and time provided by change of radix. Thus chip area utilized is roughly proportional to speed. However, initially, as the radix is increased from 2, there is a short-lived increase in speed greater than the extra area used.

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Index Terms:
Computer arithmetic, cryptography, RSA, modular multiplication, redundant number systems, higher radix, optimal speed.
Colin D. Walter, "Space/Time Trade-Offs for Higher Radix Modular Multiplication Using Repeated Addition," IEEE Transactions on Computers, vol. 46, no. 2, pp. 139-141, Feb. 1997, doi:10.1109/12.565588
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