One of the primary advantages of spread spectrum communication is its resistance to interference and jamming. However, it has the drawback of requiring the pre-establishment of a secret code between sender and receiver. This requirement can lead to scaling and security issues, especially in a broadcast setting; as a result, several “uncoordinated” approaches have been proposed that do not require a pre-established secret code. In this thesis, we examine the underlying assumptions of these approaches and their resource requirements. In particular, we develop the model of areactive jammer, parameterize it with varying levels of ability, and use this model to analyze three proposed keyless jamming mitigation techniques.We show that many of the uncoordinated spread spectrum schemes are infeasible for realistic computational powers and allocations of bandwidtheven if the attacker simply uses commercial-off-the-shelf equipment. We also show that the third scheme, BBC codes, is vulnerable to a mark-cancellation-and-insertion attack. In particular, we show how an attacker can use multiplesinusoids to “search” for a cancellation signal over the space of phase and channel condition. We also propose modifications to improve the BBC codes, which can provide more robust jamming resistance with plausible systembandwidth requirements.