Why does the finance industry uses 2TDEA instead of 3TDEA?
Is there any historical reason or technical limitations like the support by HSMs used in the industry?
The paper referred to here says simply that the financial industry has not considered 3TDEA as it does not offer extra security.
Triple-DES, noted as 3DES from here on, uses 2 keys, chosen independently at random, to DES encrypt a message multiple times. There are also ways to use 3DES with 3 different keys, but these schemes do not give a significant amount of extra security in theory and are not considered in financial systems.
3TDEA is supposed to be very secure (I am not a cryptanalyst, but I want to be one), but why has it not been considered?
I think I am missing something big/fundamental here. Can you please help?
P.S: this is not my homework or anything.