I propose an implementation of the quantum private query protocol as described in an article using a photon to encode a question and reflectionor transmission of the photon as answer options. Each question is represented by a photon in a transmission line with both ends returning to the user, and the answer is represented by reflection or transmission of this photon caused by the single photon transistor as described in another article. By solving the quantum Langevin equations for the 32 × 32-dimensional operators describing the single photon transistor the system is analysed. This analysis shows that the user privacy is maintained when the returning transmission lines are under the user's control. The probabilities for reflection and transmission are calculated to verify the behaviour of the answering mechanism. By using pulse trains instead of numbered lines to represent questions, the scalability of the system could be improved.