Secure multiparty sum computation corruption bound
For just computing a sum, the information-theoretic bound (assuming semihonest) is $t&lt;n-1$.

Why $n-1$ and not $n$?
In the case of $t&lt;n$, we can allegedly tolerate up to $n-1$ corrupt parties. If we are computing a sum, and the $n-1$ parties know the sum $S$ and their own inputs ($x_i$), they can simply compute the sum of their inputs and subtract that from $S$ to learn the private input of the single honest party. Therefore, there must be at least two honest parties if we are computing the sum.