Yap they tried but it was experimental. They want something practical. Well they might have solved the problem but I kind of doubt it. Notice that instead of a

Yap they tried but it was experimental. They want something practical. Well they might have solved the problem but I kind of doubt it. Notice that instead of a number it could be a set of random dictionary words. So instead of 123 they get "potato airplane". Now Alice and Bob start making jokes or comments about how silly that sounds and how far potato airplanes could fly etc. Now the problem of simply transcribing individual numbers got many times more complicated.