chris-belcher

Design for a CoinSwap Implementation for Massively Improving Bitcoin Privacy and Fungibility

25/5/2020

Abstract

Imagine a future where a user Alice has bitcoins and wants to send them with maximal privacy, so she creates a special kind of transaction. For anyone looking at the blockchain her transaction appears completely normal with her coins seemingly going from address A to address B. But in reality her coins end up in address Z which is entirely unconnected to either A or B.

Now imagine another user, Carol, who isn't too bothered by privacy and sends her bitcoin using a regular wallet which exists today. But because Carol's transaction looks exactly the same as Alice's, anybody analyzing the blockchain must now deal with the possibility that Carol's transaction actually sent her coins to a totally unconnected address. So Carol's privacy is improved even though she didn't change her behaviour, and perhaps had never even heard of this software.

rustyrussell

#include <ccan/array_size/array_size.h>
#include <ccan/asort/asort.h>
#include <ccan/crypto/sha256/sha256.h>
#include <ccan/err/err.h>
#include <ccan/str/hex/hex.h>
#include <ccan/short_types/short_types.h>
#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
#include <SDL2/SDL_pixels.h>

niftynei

{
  "annotations": {
    "list": [
      {
        "builtIn": 1,
        "datasource": "-- Grafana --",
        "enable": true,
        "hide": true,
        "iconColor": "rgba(0, 211, 255, 1)",
        "name": "Annotations & Alerts",

LnL7

# This expression returns a list of all fixed output derivations used by ‘expr’.
# eg.
# $ nix-instantiate find-fixed-outputs.nix --eval --strict --json --arg expr '(import <nixpkgs> {}).hello'

with import <nixpkgs> { };
with lib;

{ expr }:

let

pervognsen

A quadratic space is a real vector space V with a quadratic form Q(x), e.g. V = R^n with Q as the squared length. The Clifford algebra Cl(V) of a quadratic space is the associative algebra that contains V and satisfies x^2 = Q(x) for all x in V. We're imposing by fiat that the square of a vector should be the quadratic form's value and seeing where it takes us. Treat x^2 = Q(x) as a symbolic rewriting rule that lets you replace x^2 or x x with Q(x) and vice versa whenever x is a vector. Beyond that Cl(V) satisfies the standard axioms of an algebra: it lets you multiply by scalars, it's associative and distributive, but not necessarily commutative.

Remarkably, this is all you need to derive everything about Clifford algebras.

Let me show you how easy it is to bootstrap the theory from nothing.

We know Cl(V) contains a copy of V. Since x^2 = Q(x) for all x, it must also contain a copy of some nonnegative reals.

nothingmuch

Motivation

Locking down REST and/or JSON-RPC APIs in a generic way, with an object capability security model.

Proposed Design

Given some sort of priviliged access to a backend, this proxy would expose the service with no changes to the API apart from additional requirement for macaroon authorization.

A second mode would also be able to expose such a service to an unrestricted port, by statically configuring a macaroon to be submitted to an upstream endpoint, allowing hardened APIs to be exposed with no macaroon required.

syuhei176

const primeNumberList = require('prime-number/list')
const BigNumber = require('bignumber.js');
const utils = require('ethereumjs-util');

// const primeNumberList = [3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47];

BigNumber.config({
  DECIMAL_PLACES: 2,
  ROUNDING_MODE: BigNumber.ROUND_FLOOR
})

jhoenicke

#!/usr/bin/env python3
import hashlib
import binascii
import os

from trezorlib import log
from trezorlib.client import TrezorClient
from trezorlib.transport import get_transport
from trezorlib.tools import parse_path

Nadrieril

# I used this shell.nix to build LineageOS 13.0 for my maguro (Samsung Galaxy Nexus GSM) phone
# The build instructions for normal Linuxes are here: https://wiki.lineageos.org/devices/maguro/build
# For NixOS, follow those instructions but skip anything related to installing packages
# Detailed instructions:
#   cd into an empty directory of your choice
#   copy this file there
#   in nix-shell:
#    $ repo init -u https://github.com/LineageOS/android.git -b cm-13.0
#    $ repo sync
#    $ source build/envsetup.sh

jonasschnelli

  BIP: ??? (tbr after sending to mailing list)
  Layer: Applications
  Title: Cipherseed – encrypted wallet seed
  Author&#58; Jonas Schnelli <dev@jonasschnelli.ch>
  Comments&#45;Summary&#58; No comments yet.
  Comments&#45;URI&#58; 
  Status&#58; Draft
  Type&#58; Standards Track
  Created&#58; 2018&#45;06&#45;04