Alice and Bob want to know if two strings of length $n$ are
almost equal. That is, do they differ on at most $a$ bits?
Let $0\le a\le n-1$.
We show that any deterministic protocol, as well as any
error-free quantum protocol ($C^*$ version), for this problem
requires at ... more >>>

Max-Satisfy is the problem of finding an assignment that satisfies
the maximum number of equations in a system of linear equations
over $\mathbb{Q}$. We prove that unless NP$\subseteq $BPP there is no
polynomial time algorithm for the problem achieving an
approximation ratio of $1/n^{1-\epsilon}$, where $n$ is the number
of ... more >>>

We consider the problem of traversing skew (unbalanced) Merkle
trees and design an algorithm for traversing a skew Merkle tree
in time O(log n/log t) and space O(log n (t/log t)), for any choice
of parameter t\geq 2.
This algorithm can be of special interest in situations when
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