Re: [GD-General] serial numbers

[<cas...@ya...>]

Thanks a lot for your explanation, now I understand.


Ignacio Castaño
cas...@ya...


Gareth Lewin wrote:
> Hmm, say (for arguments sake) that your hash is 12 characters. The
> sequential number is 4 characters.
>
> My name is Gareth Lewin, the code you give me is
>
> 0001-2486-2546-1356
>
> 2486-2546-1356 is the hash of "Gareth Lewin 0001"
>
> if another Gareth Lewin registered your product, you create the hash for
> "Gareth Lewin 002" and say that is 4532-5634-1867 so his key is
> 0002-4532-5634-1867
>
> Ofcourse you need to make sure your hash function generates vastly
differant
> values for "Gareth Lewin 001" and "Gareth Lewin 002"
>
> You can do that by taking the 4 digits as a hex number and xoring "Gareth
> Lewin" with it and hashing.
>
> So you generate a hash for "Gareth Lewin" xored (each 4 chars) by 0001
etc.
> This would work nicely if (and that's the case you describe) the hash
> function runs on a remote machine.
>
> This stuff won't work really well on the clients machine.
>
> Another idea is to have 255 or more secrets ( You can just take a
> dictionary, randomise it and use that as the secret table ), then the
> sequential number is just the index into the table.