Not sure if that touches the core of the discussion.
First, this is not an issue of secure network complex, but one of trusted computing, where network itself may as well be "totaly unprotected/unsafe" (conditionally saying for illustrative purpose), but participants exchange "unhackable" secure messages. It is a democratization of the network security, shifting the security issue to its participant.
(an extreem point of view)
Banks, control secure electronic lockboxes in a different implementation space, then the one addressed here. That is on a institutional level, not on a retail side where retail space transacts with banks/OLbrokers over the internet.
So, for banks, being a financial service providers, the migration path to trusted computing does not have to be ALL or NONE, but it can be gradual, following the path of market acceptance of TC. It can be implemented in parallel with the existing means of secure online trasacting.
Market Data 
Markets 
AI
