  In this paper, we investigate how constraints on the randomization in the
encoding process affect the secrecy rates achievable over wiretap channels. In
particular, we characterize the secrecy capacity with a rate-limited local
source of randomness and a less capable eavesdropper's channel, which shows
that limited rate incurs a secrecy rate penalty but does not preclude secrecy.
We also discuss a more practical aspect of rate-limited randomization in the
context of cooperative jamming. Finally, we show that secure communication is
possible with a non-uniform source for randomness; this suggests the
possibility of designing robust coding schemes.
