I am going to organise a quest for teenagers.

I have a vintage phone like below:

enter image description here

I am looking for ideas how to use the rotary phone with numbers 1,2, ..., 9, 0 and letters A, B, C, F, H, I, K, L, M, R.

My attempt is: to use a "A1Z26" cipher (in my case A1R0), for instance, 3188 - CALL, 2188 - BALL, 619 - I AM, 4188 - FALL, 7688 - KILL, 2688 - BILL.

What is an alternative to the substitution cipher?


You can get a bit more excitement from the letters if you assign each number to a range, albeit an irregular one.

So 1=A, 2=B, 3=C,D,E, 4=F,G, 5=H, 6=I,J, 7=K, 8=L, 9=M,N,O,P,Q, and 0=R,S,T,U,V,W,X,Y,Z.

So for example PUZZLING STACK EXCHANGE becomes 90008694 00137 30351943.

To decode, reverse the process. With some of the letters fixed, guessing the others should be easy enough.

  • 1
    $\begingroup$ If the phone has actual letters marked on it, then using a different correspondence between letters and digits seems likely to be really confusing... $\endgroup$ – Gareth McCaughan Dec 1 '19 at 10:50
  • 1
    $\begingroup$ @GarethMcCaughan; fixed - it was very early... $\endgroup$ – JMP Dec 1 '19 at 11:30

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.