  Inspired by recent work by Christensen and Popovski on secure $2$-user
product computation for finite-fields of prime-order over a quantum multiple
access channel, the generalization to $K$ users and arbitrary finite fields is
explored. Asymptotically optimal (capacity-achieving for large alphabet)
schemes are proposed. Additionally, the capacity of modulo-$d$ ($d\geq 2$)
secure $K$-sum computation is shown to be $2/K$ computations/qudit,
generalizing a result of Nishimura and Kawachi beyond binary, and improving
upon it for odd $K$.
