A system, method and computer-readable medium for data breach simulation and impact analysis in a computer network, including generating an exposure matrix corresponding to data stores connected to the computer network, the exposure matrix storing a correspondence between regulations and an exposure of each data store the regulations, generating approximation matrices from the exposure matrix by iteratively applying a data compression algorithm to the exposure matrix, each successive iteration of the data compression algorithm being configured to more closely approximate the exposure matrix than a previous iteration of the data compression algorithm, simulating a plurality of data breach and mitigation scenarios on the plurality of data stores based at least in part on the plurality of approximation matrices to determine an overall impact of each data breach and mitigation scenario, determining an optimal data breach and mitigation scenario in the plurality of data breach and mitigation scenarios.