 The de-identification process involves masking, generalizing or deleting both direct and indirect identifiers; the definition of this process is not universal, however.Information in the public domain, even seemingly anonymized, may thus be re-identified in combination with other pieces of available data and basic computer science techniques.The Protection of Human Subjects ('Common Rule#Signatories'), a collection of multiple U.S. federal agencies and departments including the U.S. Department of Health and Human Services, speculate that re-identification is becoming gradually easier because of "big data"—the abundance and constant collection and analysis of information along the evolution of technologies and the advances of algorithms.