Filter for checking for duplicate entries in database

A method of adding records to a database, comprising:

• a) maintaining several databases,
• i) each database corresponding to a respective bank, or bank branch, and
• ii) each database containing financial records of bank customers;
• b) for each database, using an algorithm to generate a plurality of signatures, one for each record in the database, wherein
• i) two identical records always cause the algorithm to produce two identical signatures;
• and
• ii) two different records sometimes cause the algorithm to produce two identical signatures;
• c) storing the signatures;
• d) when a new record is to be added to a target database,
• i) using the algorithm to generate a new signature for the new record;
• ii) comparing the new signature with the stored signatures of the target database;
• iii) if the new signature does not match a stored signature of the target database, then adding the new record to the database;
• iv) if the new signature does match a stored signature of the target database, then searching records in the target database, and
• A) if the searched records do not match the new record, then adding the new record to the database;
• and
• B) if the new record matches one of the searched records, calling for human intervention.