Permutable Chebyshev polynomials (T polynomials) defined over the field of real numbers are suitable for creating a Diffie-Hellman-like key exchange algorithm that is able to withstand attacks using quantum computers. The algorithm takes advantage of the commutative properties of Chebyshev polynomials of the first kind. We show how T polynomial values can be computed faster and how the underlyi...

convergent for \z\ < p, where p > 0, then f(z) is said to have a fixpoint of multiplier ax at 2 = 0. In the (local) iteration of/(?) one studies the sequence {/„(*)},» = 0, 1, 2, • • • in a neighbourhood of z — 0, /n(z) being defined by /oto = * . / « « = / 0 i t o } ^r » = 1 , 2 , 3 , . . . For many values of the multiplier ax, including 0 < \ax\ < 1 and \ax\ > 1, the local iteration of f(z) i...