Patent attributes
A method and system of masking a group of related data values. A record in an unmasked data file of n records is read. The record includes a first set of data values of data elements included in a related data group (RDG) and one or more data values of one or more data elements external to the RDG. A random number k is received. A second set of data values is retrieved from a lookup table that associates n key values with n sets of data values. Retrieving the second set of data values includes identifying that the second set of data values is associated with a key value of k. The n sets of data values are included in the umnasked data file's n records. The record is masked by replacing the first set of data values with the retrieved second set of data values.