Imagine a situation where Alice has an account with $100 in it. This is a special kind of account that allows her to give out special spending limit codes to her friends which allow them to in turn to give out their own spending-limit codes.
For example, imagine this set of signed messages:
- “Bob may withdraw up to $100 from my account” - Alice, signed 5/8/2018
- “Carol may withdraw up to $50 of my allowance from Alice” - Bob, signed 7/6/2018 (includes reference to previous Alice message)