We address the problem of jamming-resistant communication in scenarios in which the communicating parties do not share secret keys. This includes scenarios where the communicating parties are not known in advance or where not all parties can be trusted (e.g., jamming-resistant key establishment or anti-jamming broadcast to a large set of unknown receivers). In these cases, the deployment of shared secret keys is unrealistic, and therefore this problem cannot be solved using existing anti-jamming solutions like FHSS and DSSS that depend on pre-shared keys. Recently, a solution to this problem has been proposed that introduces Uncoordinated Frequency Hopping (UFH), a new spread-spectrum anti-jamming technique that does not rely on secret keys. In this work, we investigate the effciency of UFH-based communication: we identify optimal strategies for the UFH frequency channel selection and we propose a set of new UFHbased anti-jamming schemes that, compared to the original UFH proposal, reduce the communication latency up to one-half (i.e., increase UFH communication throughput up to two times).