Abstract: A data set can be analyzed for the presence of sensitive data using type-specific validation mechanisms to test data within the data set that superficially matches a corresponding data type format. In general, a type-specific validation mechanism may be applied to data segments within the data set when they match the data type format, and used to cumulatively build a statistical inference about whether the data set contains the corresponding data type. This technique may usefully be applied in a range of security contexts, such as characterizing data at rest or detecting leakage of sensitive data during a data transmission.