We show that given a PRFG (pseudo-random function generator) G which is $ \frac{1} {c} - $ \frac{1} {c} - partially secure, the construction $ \frac{1} {c} - $ \frac{1} {c} - $ \frac{1} {c} - $ \frac{1} {c} - produces a strongly secure PRFG, where g _i ∈ G and r _i are strings of random bits. Thus we present the first “natural” construction of a (totally secure) PRFG from a partially secure PRFG. Using results of Luby and Rackoff, this result also demonstrates how to “naturally” construct a PRPG from partially secure PRPG.