 In the digital world, similar substitution techniques have been used since the 1970s as a means to isolate real data elements from exposure to other data systems.In databases for example, surrogate key values have been used since 1976 to isolate data associated with the internal mechanisms of databases and their external equivalents for a variety of uses in data processing.More recently, these concepts have been extended to consider this isolation tactic to provide a security mechanism for the purposes of data protection.