Ruggero Lanotte, Andrea Maggiolo-Schettini, Simone Tini, Angelo Troina, and Enrico Tronci. "Automatic Analysis of the NRL Pump." Electr. Notes Theor. Comput. Sci. 99 (2004): 245–266. DOI: 10.1016/j.entcs.2004.02.011.
Abstract: We define a probabilistic model for the NRL Pump and using FHP-mur$\varphi$ show experimentally that there exists a probabilistic covert channel whose capacity depends on various NRL Pump parameters (e.g. buffer size, number of samples in the moving average, etc).