This isn't obviously crypto-related, but I'll explain if there's a simple
solution.
Given that f(x+1) = f(x) * f(x) + c, does anybody know how to express f(x)
in closed form?
-Bram Cohen
It turns out my memory of what it's difficult to find square roots modulo
was wrong. The fixed version is below.
Alice wants to force Bob to do w 'units' of computation in such a way that
he can't do the computation in parallel and she can verify the result
expending relatively little resources.
At 12:50 PM 3/25/00 -0800, Bram Cohen wrote:
Given that f(x+1) = f(x) * f(x) + c, does anybody know how to express f(x)
in closed form?
Well... That's an example of an iterated nonlinear map. Such things have
been extensively studied. For some values of c, for some initial
conditions, the
