Before revision:  We present an approach to pooled testing, based on the geometry of a hypercube , which enables fast, cost-effective identification of infected people when the prevalence of the virus is low .
After revision:  We present an approach to pooled testing, based on the geometry of a hypercube . At low prevalence, this testing procedure uniquely identifies infected individuals in a small number of tests. We discuss the optimal group size and explain why, given the highly infectious nature of the disease, parallel searches are preferred. We report proof of concept experiments in which a positive sample was detected even when diluted a hundred-fold with negative samples. Using these methods, the costs of mass testing could be reduced by a factor of ten to a hundred or more. If infected individuals are quickly and effectively quarantined, the prevalence will fall and so will the costs of regularly testing everyone. Such a strategy provides a possible pathway to the longterm elimination of SARS-CoV-2 .