Python3 (3.2.5) + changes + additions

[username1565]

Hello. If you want, you can create another branch for python3,
and save this there, then test, and fix something.

Changes:

1. mini_esdsa.py.
	Rewrite for Python 3.2.5
	Add additional functions:
	- fast pow_mod, to check is point on curve or not - faster.
	- add () for print operator.
	- remove space at line 202
	- add pow_mod as parameter for contains function. By default this is 0,
		and function can be called with two parameters.
	- add comment for additive inversion
	- add functions to subtract, divide, get Y-coordinate and Point, by X-coordinate and parity.
	- fix mult_inv function. Now this return tuple with gcd, if this not 1.
	- add two optional parameters for brute-force function. start=0, and show_each=0; by default this is nulls.
		start=N run brutefource from specified start-number,
		show_each=M - show the new start number, after each M checked invalid points.
	- for baby-step-giant-step method, add optional parameter m=0, because this was been hardcoded as sqrt(n).
		See comments there.
	- maybe giant steps need to be fixed...
	- add additional cycle to restart pollard_rho, because sometimes this is not working, when mult_inv is incorrect.
		Now this restarting, if mult_inv return tupple, not nubmer.
	- add test function
	- run one test as demo.
	- add commented test in cycle.

2. Readme.md - Fixed. Maybe need to add some additional commands there.

[qubd]

Cool! Thanks for doing this and letting me know.

I have no time for maintaining this repo at the moment, but at the end of the term (December) I'll look over your changes and merge them here. I'll also either make a python 3 branch, or add a link in the readme to your fork.

[username1565]

If you have free time, you can test and try to optimize Elliptic-Curve-Cryptography.
Just for fun. See my ideas in the source code.
And... This is working!

Best regards.

[qubd]

Just migrated to python3 with minimal changes. No intentions to optimize performance or add more functionality at the moment. I'd like to keep this repo minimal and let others fork it and have fun with that!

I'll look into the problems with the baby-step giant-step and pollard rho methods over the next few days.

[qubd]

Turns out I didn't end up looking into the baby-step giant-step and rho issues over the next few days. =]

Now I have time though.

It appears at first glance that the problems in these methods arise only when making use of the extensions you've added. In the case of baby-step giant-step, when the optional argument is used, and in the case of rho, when the subgroup order n is not prime.

I've added some comments to make it clear that some of the methods require the order of the subgroup to be prime (in fact, I wrote all of the code here under that assumption, this is briefly mentioned in the readme).

If you have a example where the original baby-step giant-step procedure goes wrong, or where the rho procedure fails when the subgroup order is prime, let me know.

Thanks again for the contribution. I would eventually like to add Diffie-Hellman to this module, so I may yet merge some of your changes in, but it likely won't happen anytime soon.