In the work presented, we propose a pseudorandom bit generator using Rubik's Cube, a three dimensional puzzle to produce random bits using the mixing property of the puzzle.
The proposed pseudorandom bit generator is explained in Section 3.
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Pseudorandom Bit Generator Based on the Chebyshev Polynomial.
The proposed pseudorandom bit generator is based on two Chebyshev polynomials, as described by
The proposed pseudorandom bit generator is based on two Duffing maps, given by the following equations:
We tested output of the two strings of 125000000 bytes of the proposed Chebyshev polynomial based pseudorandom bit generator and Duffing map based pseudorandom bit generator, respectively.
In Section 2, we propose two pseudorandom bit generators (PRBGs): one based on Chebyshev polynomial and the other based on Duffing map.
In 2003 Kocarev and Jakimoski  discussed the different possibilities of using chaotic maps as pseudo-random number generators and also constructed a chaos-based pseudorandom bit generator
. In 2004 Fu et al  proposed a chaos-based random number generator using piecewise chaotic map.
He begins by introducing the topic and the cryptographic systems used today, then addresses each in turn, with discussion of one-way functions, hash functions, random bit generators, symmetric and asymmetric encryption systems, message authentication codes, pseudorandom bit generators
and functions, digital signature systems, key establishment, entity authentication, secure multiparty computation, and key management.