The presently disclosed technology is directed to combatting data theft, particularly of verified authentication data (or hashes thereof) such as login information, thumbprint data, digital signatures, identification numbers, and any other data that should be known to an accessor of stored data. The verified authentication data is initially saved for later comparison in a new type of memory, write-and-compare-only memory, where the data may be queried as to whether a to-be-verified value matches the stored verified value, but the stored and verified data is not read from the write-and-compare-only memory. This prevents a data breach by preventing the verified authentication data from being read by anyone, including those with access (whether legitimate or illegitimate) to any system connected to the write-and-compare-only memory.