It is literally a ring with 2 bands, one band contain letters, other band something else for example numbers. You write number from second band while using letters from first for reference, for decoding you need ring with same letter/number pairing of course. Very primitive kind of code.
It is literally a ring with 2 bands, one band contain letters, other band something else for example numbers. You write number from second band while using letters from first for reference, for decoding you need ring with same letter/number pairing of course. Very primitive kind of code.