[ZephyrP]

of course, but an LFSR is going to be faster (provided you have a reasonable number of rounds in your Feistel cipher), have some situationally desirable statistical properties and is easier to adapt than a format-preserving encryption technique like a Feistel network.

[wslh]

Sorry, but faster for the computing capabilities we have in every electronic device is no significant in the application. I have not seen a customer inquiring about the speed of this process. They were looking to a method that is more secure than others.

For example, in the case of Philip Morris was about winning prizes and imagine if they tried other methods before where some smart people reversed the method.