A method and system for consistent format preserving encryption (C-FPE) are provided to protect data while the data is in a domain while allowing encrypted data to be treated inside the domain as if it were the unencrypted data. The method includes inserting a coupling into a data flow at a perimeter of the domain, and translating a data element from an unprotected data element to a protected data element using the coupling such that the data element is a protected data element within the domain.