I don't think that helps, because the address space of numbers is too small so anything is reversible. My solution to this was to generate 99 extra random numbers that start with the same digits as the real one and send them all to the server. The front-end then shows just the result the user cares about but the back-end doesn't know which is which.

https://www.thenewseachday.com/private-facebook-phone-number...

There is a movie from the 80s called Wargames that you might enjoy.