1. A system for secure data exchange and data tampering prevention, the system comprising: a secure data system configured to receive a plural number of electronic data files from a respective plurality of data entities via secure communication over a network, and store the received electronic data files in a first storage of the secure data system, each electronic data file comprising data values collected by a respective one of the data entities over a predefined time period; and a benchmark data generator system communicatively coupled to the secure data system, the benchmark data generator system comprising: a randomized snapshot generator configured to determine, after the predefined time period, a plural number of randomized snapshot times corresponding to the predefined time period; plural second storage corresponding to the plural number of randomized snapshot times; and a synthetic data generator configured to: a) create a data mapping between the first storage and the plural second storage, based on the randomized snapshot times and the plural number of electronic data files and b) selectively transfer samples of the data values in each electronic data file from the first storage to the plural second storage according to the data mapping, such that each second storage stores corresponding samples synthesized from among all of the data entities associated with a single respective randomized snapshot time.