We investigate the computational complexity of the Boolean Isomorphism problem (BI):
on input of two Boolean formulas F and G decide whether there exists a permutation of
the variables of G such that F and G become equivalent.

Our main result is a one-round interactive proof for $\overline{BI}$, ... more >>>

We investigate the computational complexity of the
isomorphism problem for one-time-only branching programs (BP1-Iso):
on input of two one-time-only branching programs B and B',
decide whether there exists a permutation of the variables of B'
such that it becomes equivalent to B.

Our main result is a two-round interactive ... more >>>

For a permutation group $G$ acting on the set $\Omega$
we say that two strings $x,y\,:\,\Omega\to\boole$
are {\em $G$-isomorphic} if they are equivalent under
the action of $G$, \ie, if for some $\pi\in G$ we have
$x(i^{\pi})=y(i)$ for all $i\in\Omega$.
Cyclic Shift, Graph Isomorphism and ... more >>>

Given two $n$-variable boolean functions $f$ and $g$, we study the problem of computing an $\varepsilon$-approximate isomorphism between them. I.e.\ a permutation $\pi$ of the $n$ variables such that $f(x_1,x_2,\ldots,x_n)$ and $g(x_{\pi(1)},x_{\pi(2)},\ldots,x_{\pi(n)})$ differ on at most an $\varepsilon$ fraction of all boolean inputs $\{0,1\}^n$. We give a randomized $2^{O(\sqrt{n}\log(n)^{O(1)})}$ algorithm ... more >>>