I've got the following theoretical problem which puzzles me a bit:
I can obtain a string of n bytes (as octets, one byte = one octet = eight bits) of random data. I need to preserve the randomness while reducing the base from 256 to x where x is below 256 (and not 0, 1, 2, 4, 8, 16, 32, 64 or 128).
As I want to preserve the randomness, I don't want to cut-off (waste) any information from this string until I've obtained the number of chunks I need. This is for reason of randomness which can be a limited resource on the computer.
I had the idea to do this for base64 which is simple because I can just create 4 numbers out of a single byte (by shifting bits for example: encode64()). But how to do with a base like 254 for example? I can not cut off at bit-boundaries here, can I?
Do I probably need to create a number large enough out of base 2 based bits that can contain both bases? (This is one of the ideas I have so far).
Would be great to get some feedback, I normally paint pictures with such problems, however, just discovered this website here yesterday and I normally use Stackoverflow so I thought I give it a try :D
If you're interested in some non-theoretical background to my question, see "What is the meaning of the term “simple string” for the SALT string in Unix crypt using SHA-256 and SHA-512?", you might get an idea why I don't want to loose any information bits from the random source.