Armin Sabouri arminsabouri

bitcoin privacy related bookmarks

protocols

Blind Diffie-Hellman Key Exchange (blind ecash)

The goal of this protocol is for Bob to get Alice to perform a Diffie-Hellman key exchange blindly, such that when the unblinded value is returned, Alice recognizes it as her own, but can’t distinguish it from others (i.e. similar to a blind signature).

Alice:
A = a*G
return A

Bob:
Y = hash_to_curve(secret_message)
r = random blinding factor

OP_CAT Enables Scalar Multiplication for EC Points

CAT can reduce curve point scalar multiplication to a subtraction in the scalar field.

Subtraction of field elements can probably be emulated in less than 250 (?) opcodes. For now, let's assume we had an (emulated) opcode, op_scalar_sub, for subtracting two elements of the scalar field of secp256k1.

Given secp's generator G, we want to compute for some scalar r the point R = rG

That is possible by hacking it into a Schnorr signature (R,s) for the key P = xG = 1G = G

	{url:'stun:stun01.sipphone.com'},
	{url:'stun:stun.ekiga.net'},
	{url:'stun:stun.fwdnet.net'},
	{url:'stun:stun.ideasip.com'},
	{url:'stun:stun.iptel.org'},
	{url:'stun:stun.rixtelecom.se'},
	{url:'stun:stun.schlund.de'},
	{url:'stun:stun.l.google.com:19302'},
	{url:'stun:stun1.l.google.com:19302'},
	{url:'stun:stun2.l.google.com:19302'},

	/*
	* A simple example of json string parsing with json-c.
	*
	* clang -Wall -g -I/usr/include/json-c/ -o json_parser json_parser.c -ljson-c
	*/
	#include <json.h>
	#include <stdio.h>

	int main() {
	struct json_object *jobj;

	/*
	* Handling Errors using async/await
	* Has to be used inside an async function
	*/
	try {
	const response = await axios.get('https://your.site/api/v1/bla/ble/bli');
	// Success 🎉
	console.log(response);
	} catch (error) {
	// Error 😨