It is a long-standing open question whether the average-case hardness of NP implies the existence of a one-way function. The hypothetical world in which this does not hold is called Pessiland, which is the most pessimistic among Impagliazzo's five possible worlds. In this paper, we present the first "sharp" characterization ... more >>>

We consider the worst-case hardness of the gap version of the classic time-bounded Kolmogorov complexity problem—$Gap_pMK^tP[s_1,s_2]$—where the goal is to determine whether for a given string x, $K^t(x) ?s_1(n)$ or $K^{p(t)}(x) > s_2(n)$, where $K^t(x)$ denotes the t-bounded Kolmogorov complexity of x. As shown by Hirahara (STOC’18), if $Gap_pMK^tP[s_1,s_2] \notin ... more >>>

In this paper we study the cryptographic complexity of non-trivial witness-indistinguishable ($WI$) arguments of knowledge. We establish that:

- Assuming that $NP\not\subseteq P/poly,$ the existence of a constant-round computational $WI$ argument of knowledge for $NP$ implies that (infinitely-often) auxiliary-input one-way functions exist.

- Assuming that $NP\not\subseteq P^{Sam}/poly,$ there is no ... more >>>