We consider the problem of delegating computation of group operations from a computationally weaker client holding an input and a description of a function, to a {\em single} computationally stronger server holding a description of the same function. Solutions need to satisfy natural correctness, security, privacy and efficiency requirements. We obtain delegated computation protocols for the following functions, defined for an {\em arbitrary} commutative group:
\begin{enumerate}
\item Group inverses, with security and privacy holding against any computationally unrestricted malicious server.
\item Group exponentiation, with security and privacy holding against any computationally unrestricted ``partially honest" server.
\item Group exponentiation, with security and privacy holding against any polynomial-time malicious server, under a pseudorandom generation assumption, and security holding with constant probability.
\end{enumerate}
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