  In this paper, a lightweight three-user secure quantum summation protocol is
put forward by using single-particle states, which can accomplish the goal that
three users cooperate together to calculate the modulo 2 addition of their
private messages without the help of a third party. This protocol only requires
single-particle states rather than quantum entangled states as the initial
quantum resource, and only needs single-particle measurements and Bell basis
measurements. This protocol needs none of quantum entanglement swapping, the
Pauli operations, the controlled-not (CNOT) operation, the Hadamard gate or a
pre-shared private key sequence. Security analysis proves that this protocol is
secure against both the outside attacks and the participant attacks. Compared
with the existing two-dimensional three-user quantum summation protocols, this
protocol more or less takes advantage over them on the aspects of the initial
quantum resource, users' quantum measurement, the usage of quantum entanglement
swapping, the usage of Pauli operations, the usage of CNOT operation or the
usage of Hadamard gate.
