A SIMPLE UNPREDICTABLE PSEUDORANDOM NUMBER GENERATOR
A SIMPLE UNPREDICTABLE PSEUDORANDOM NUMBER GENERATOR
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DOI:
10.1137/0215025
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发表时间:
1986-05-01
影响因子:
1.6
通讯作者:
SHUB, M
中科院分区:
文献类型:
--
作者:
BLUM, L;BLUM, M;SHUB, M
Two closely-related pseudo-random sequence generators are presented: Thegenerator, with inputPa prime, outputs the quotient digits obtained on dividing 1 byP. Thegenerator with inputsN,(whereis a product of distinct primes, each congruent to 3 mod 4, andis a quadratic residue), outputswhereand.From short seeds each generator efficiently produces long well-distributed sequences. Moreover, both generators have computationally hard problems at their core. The first generator’s sequences, however, are completely predictable (from any small segment ofconsecutive digits one can infer the “seed,”P, and continue the sequence backwards and forwards), whereas the second, under a certain intractability assumption, is unpredictable in a precise sense. The second generator has additional interesting properties: from knowledge ofandNbut notPorQ, one can generate the sequence forwards, but, under the above-mentioned intractability assumption, one can not generate the sequence backwards. From the additional knowledge ofPandQ, one can generate the sequence backwards; one can even “jump” about from any point in the sequence to any other. Because of these properties, thegenerator promises many interesting applications, e.g., to public-key cryptography. To use these generators in practice, an analysis is needed of various properties of these sequences such as their periods. This analysis is begun here.