Replacing distinct data in a relational database with a distinct reference to that data and distinct de-referencing of database data

A tangible, non-transitory, machine-readable medium storing instructions that when executed by one or more processors effectuate operations comprising:

• obtaining, with one or more processors, criteria to select plain-text values in, or requested to be written to, a lower-trust database;
• selecting, based on the criteria, a first plain-text value stored in, or requested to be stored in, a first entry in the lower-trust database;
• in response to selecting the first plain-text value, determining, with one or more processors, a first reference value, wherein:
• the criteria indicate whether the plain-text values are to be stored in the lower-trust database or a higher-trust database;
• the lower-trust database stores relationships between both plain-text values stored in the lower-trust database and plain-text values stored in the higher-trust database;
• and
• the first reference value does not reveal the first plain-text value without access to the higher-trust database;
• storing, with one or more processors, the first plain-text value in the higher-trust database in a second entry identified by the first reference value;
• storing, with one or more processors, the first reference value in the first entry of the lower-trust database;
• selecting, with one or more processors, another instance of the first plain-text value stored in, or requested to be stored in, a third entry in the lower-trust database, the third entry being a different entry from the first entry;
• and
• in response to selecting another instance of the first plain-text value stored in, or requested to be stored in, the third entry in the lower-trust database, storing, with one or more processors, a value associated with, or equal to, the first reference value.