Python Bitcoin ECC library, supports signing, transactions, determinstic wallets

[danneu]

Huge thanks for sharing.

This is the most intelligible/simple implementation I've found yet, and not just for ECC.

[1538086654]

1538086654

[deepceleron]

You can grab line 573-590 out of here if you want to add a "print paper wallet" def print_wallet(priv) to your code:

http://we.lovebitco.in/dice2key.py

Or grab the whole thing to line 483 if you want a pretty version of main.py, but there's still some warnings for python 2.7:

Expected type 'Number', got 'str | unicode' instead (at line 429) (edit: this appears to be an invalid warning I can't make go away)
Unexpected argument (at line 92) (incorrect call argument) (edit: VB fixed this)
472-475 "Q and Qr" are uppercase
redundant parenthesis. 94, 98, 103, 107, 112, 162, 167, 169

along with more PEP8 if: statements on same line, spacings etc.

[phelix]

Thanks for the commit!

My pleasure. PBT is great.

[sdp]

Nice, congratulations. Though I would've suggested a different language cause simply Python ain't all that fast when it comes to these expensive operations there.

This reminds me when someone mentioned to me that I shouldn't use iostreams in C++.  That it was faster to use C-style printf functions.  After some bench marking and some inspection he was right that C++ iostreams are slower.  Each << is a function call.  I think this argument is similar.  In the end it doesn't matter.  Computers are fast today.

[phelix]

I assume mktx will put anything not spent explicitly to mining fees?

[waxwing]

Are there any practical limits in numbers of parties to a multisig transaction? I am thinking of a scenario like 6 of 10 of 8 of 15. Does the size of the script start to break anything at any point?

I assume mktx will put anything not spent explicitly to mining fees?

Yes, it works like that here as that's part of the bitcoin protocol.

[justusranvier]

Are there any practical limits in numbers of parties to a multisig transaction? I am thinking of a scenario like 6 of 10 of 8 of 15. Does the size of the script start to break anything at any point?

n=20 is the maximum allowed by protocol.

n>3 is currently non-standard, so you have to make a private arrangement with a miner to get those transactions included in a block.

[waxwing]

Are there any practical limits in numbers of parties to a multisig transaction? I am thinking of a scenario like 6 of 10 of 8 of 15. Does the size of the script start to break anything at any point?

n=20 is the maximum allowed by protocol.

n>3 is currently non-standard, so you have to make a private arrangement with a miner to get those transactions included in a block.

Ah thanks that is a very important point for me ... I did notice the darkwallet guys using a 3 of 5 address, I guess I can ask them about that. I only have one special use for large numbers, maybe I can work around it.

[waxwing]

(On the above posts, Vitalik seems to have added an "eligius_pushtx" method to allow the more exotic multisig txs to go through (eligius processes them apparently) so that's cool )

Question: I want to do verifying messages with addresses from external wallets
..[snipped]

Question can be ignored, the code is already there in ecdsa_recover. Thanks

[natb]

Vitalik, this is exactly what I was looking for. I'm going to replace my HW wallet test harness with your library (the one I was using before was functional, but I'd say not the cleanest library in the world). Thanks for sharing - I'll let you know if I run across any issues or have any improvement ideas.

[phelix]

the time part of the two random functions looses entropy:

str(int(time.time())**7)   is probably meant to be
str(int(time.time()**7))   or
str(time.time()**7)

It would be nice to be able to add some base entropy by hammering your tinfoil hat on the keyboard at start.

[waxwing]

I opened an issue with regard to signature padding here: https://github.com/vbuterin/pybitcointools/issues/9

I think fixing it might be a bit above my paygrade (or at least would take me a while), so if anyone can help I'd appreciate it.

Edit: Vitalik pushed a fix already, thanks (although it needs testing, which might be tricky).

[Wanesst]

That's cool!  But a different language can be better cause this ain't all that fast

[yakov]

What are you coding that needs such breakneck speed?

[hobbes]

My application of pybitcointools: offbit - Minimalistic offline key generation, offline TX signing and Tor protected TX broadcasting.

https://bitcointalk.org/index.php?topic=488915.0

[hamish.macewan]

I deliberately designed the library to be simple and no-nonsense.

Thanks for the effort, and I feel bad having to ask for assistance when so much has already been given.

What is required before you reach this point

> from pybitcointools import *

The command line examples are fine, but this "> from pybitcointools import *" only caused me grief.

[instagibbs]

I deliberately designed the library to be simple and no-nonsense.

Thanks for the effort, and I feel bad having to ask for assistance when so much has already been given.

What is required before you reach this point

> from pybitcointools import *

The command line examples are fine, but this "> from pybitcointools import *" only caused me grief.

Same here. I couldn't get it to import, even with adding the correct folders to path(even inside the script using sys.path).

I'm no linux expert though so I'm probably doing something wrong.

[waxwing]

I deliberately designed the library to be simple and no-nonsense.

Thanks for the effort, and I feel bad having to ask for assistance when so much has already been given.

What is required before you reach this point

> from pybitcointools import *

The command line examples are fine, but this "> from pybitcointools import *" only caused me grief.

"from pybitcointools import *" is Python.

If you have Python installed, you can just type 'python' (assuming it's in your path) at the command line to start the Python interpreter, and then you will get
 
>

from there you can do the above command.

Feel free to ask further questions as necessary. People will be happy to help.

[gabridome]

Thank you for all you are doing for us.
I have scarse experience in python and programming in general but I like a lot your tutorial on multisig (http://bitcoinmagazine.com/11113/pybitcointools-multisig-tutorial/).

I get the following error when I type the first line of code:
>>> from pybitcointools import *
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named pybitcointools

also using the command line tool I get instead:
 k1=`pybtctool random_key`
Traceback (most recent call last):
  File "/usr/local/bin/pybtctool", line 8, in <module>
    cmd = sys.argv[2]
IndexError: list index out of range

I work on Mac OS. I have installed the tools with:

sudo pip install bitcoin

Thank you.

[tongbao]

nice work, put a footprint here [feasibility on multiple public keys]