There are fare vending machines in fewer than half of Boston's commuter rail stations so most people buy their tickets on-board the trains. However the Massachusetts Bay Transit Authority announced today that come fall, riders may be able to prepurchase their fares on their phones.

"Want free subway rides for life?" teased the description of the talk "Anatomy of a Subway Hack" by three MIT students at DefCon this past weekend, where they planned to explain security flaws in the payment system for Boston's T subway. Live! They were going to demo how they cracked the system's CharlieCard…