Simple crypto-algorithm that uses number bases to crypt message
The best way to understand this is through hex numbers.
base-16 alphabet: 0123456789abcdf
base-16 message: bad
Now we change number base, from 16 to 10 (decimal)
base-10 alphabet: 0123456789
base-10 result: 2989
Or, from 16 to 8 (octal)
base-8 alphabet: 01234567
base-8 result: 5655
Our messages are just numbers in some base. By changing number bases, we alter our message. We just use larger bases (like 95, all ascii printable characters). So, key is a combination of alphabet, old base and new base.