Quote from: Etar on September 28, 2021, 11:36:58 AM

Here is no magic, here is script to shiftdown pubkey:

Code:

import random
import math
import hashlib
import base58
def inverse(x, p):
   """
   Calculate the modular inverse of x ( mod p )
   """
   inv1 = 1
   inv2 = 0
   n=1
   while p != 1 and p!=0:
   quotient = x // p

   inv1, inv2 = inv2, inv1 - inv2 * quotient
   x, p = p, x % p
   n = n+1

   return inv2

def dblpt(pt, p):
   """
   Calculate pt+pt = 2*pt
   """
   if pt is None:
   return None
   (x,y)= pt
   if y==0:
   return None

   slope= 3*pow(x,2,p)*pow(2*y,p-2,p)


   xsum= pow(slope,2,p)-2*x

   ysum= slope*(x-xsum)-y

   return (xsum%p, ysum%p)

def addpt(p1,p2, p):
   """
   Calculate p1+p2
   """
   if p1 is None or p2 is None:
   return None
   (x1,y1)= p1
   (x2,y2)= p2
   if x1==x2:
   return dblpt(p1, p)

   # calculate (y1-y2)/(x1-x2) modulus p

   slope=(y1-y2)*pow(x1-x2,p-2,p)


   xsum= pow(slope,2,p)-(x1+x2)

   ysum= slope*(x1-xsum)-y1


   return (xsum%p, ysum%p)

def ptmul(pt,a, p):
   """
   Calculate pt*a
   """
   scale= pt
   acc=None


   while a:

   if a&1:
   if acc is None:
   acc= scale

   else:
   acc= addpt(acc,scale, p)

   scale= dblpt(scale, p)
   a >>= 1



   return acc

def ptdiv(pt,a,p,n):
   """
   Calculate pt/a
   """
   divpt=inverse(a, n)%n
   return ptmul(pt, divpt, p)

def isoncurve(pt,p):
   """
   returns True when pt is on the secp256k1 curve
   """
   (x,y)= pt
   return (y**2 - x**3 - 7)%p == 0

def getuncompressedpub(compressed_key):
   """
   returns uncompressed public key
   """
   y_parity = int(compressed_key[:2]) - 2
   x = int(compressed_key[2:], 16)
   a = (pow(x, 3, p) + 7) % p
   y = pow(a, (p+1)//4, p)
   if y % 2 != y_parity:
   y = -y % p
   return (x,y)

def compresspub(uncompressed_key):
   """
   returns uncompressed public key
   """
   (x,y)=uncompressed_key
   y_parity = y&1
   head='02'
   if y_parity ==1:
   head='03'
   compressed_key = head+'{:064x}'.format(x)
   return compressed_key

def hash160(hex_str):
   sha = hashlib.sha256()
   rip = hashlib.new('ripemd160')
   sha.update(hex_str)
   rip.update( sha.digest() )
   return rip.hexdigest() # .hexdigest() is hex ASCII

def getbtcaddr(pubkeyst):

   hex_str = bytearray.fromhex(pubkeyst)
   # Obtain key:
   key_hash = '00' + hash160(hex_str)

   # Obtain signature:

   sha = hashlib.sha256()
   sha.update( bytearray.fromhex(key_hash) )
   checksum = sha.digest()
   sha = hashlib.sha256()
   sha.update(checksum)
   checksum = sha.hexdigest()[0:8]

   return (base58.b58encode( bytes(bytearray.fromhex(key_hash + checksum)) )).decode('utf-8')

def checkpub(realpub, temppub, id):
   localpt = ptmul(temppub, 1024, p)
   localaddpt = ptmul(g, id, p)
   respub= addpt(localpt,localaddpt, p)
   print ("respub-> ", compresspub(respub))

#secp256k1 constants
Gx=0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798
Gy=0x483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8
n=0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141
p = 2**256 - 2**32 - 977
g= (Gx,Gy)

compressed_key='0234c1fd04d301be89b31c0442d3e6ac24883928b45a9340781867d4232ec2dbdf'
point=getuncompressedpub(compressed_key)

print(getbtcaddr("04%064x%064x"%point))
print(getbtcaddr(compressed_key))
divisor = 2**3
newpub=ptdiv(point,divisor,p,n)

(partGx,partGy)=ptdiv(g,divisor,p,n)
print ("1 Fraction part-> (%x,%064x)" % (partGx,partGy))

with open('pub.txt', 'w') as f:
   f.write("04%064x%064x"%newpub)
   f.write('\n')
   print ("Compressed NewPUB (",0,")-> ", compresspub(newpub),"addr",getbtcaddr(compresspub(newpub)))
   i=1
   (pointx,pointy)=(partGx,partGy)
   while i<divisor:
   (newpubtempx,newpubtempy) = addpt(newpub,(pointx,p-pointy), p)
   f.write("04%064x%064x"%(newpubtempx,newpubtempy))
   f.write('\n')
   print ("Compressed NewPUB (",i,")-> ", compresspub((newpubtempx,newpubtempy)),"addr",getbtcaddr(compresspub((newpubtempx,newpubtempy))))
   (pointx,pointy) = addpt((pointx,pointy),(partGx,partGy), p)
   i=i+1

In this example i use pubkey 0234c1fd04d301be89b31c0442d3e6ac24883928b45a9340781867d4232ec2dbdf, privkey is 0x67 and upper range is 2^7
Divisor is 2^3, so new upper range is 2^7-2^3=2^4
In file pub.txt you will find all pubkeys and their number is equil to divisor.
if you try to find all this keys in range 0x1:0xf you will see that only one pubkey will be lie in range
And this pubkey is 03d01115d548e7561b15c38f004d734633687cf4419620095bc5b0f47070afe85a with privkey 0xC
To produce real privkey need multiply privkey by divisor
0xC*0x8 = 0x60
After this need add to result founded public key number (7)
Totaly privekey = 0x60 +0x7=0x67

Hi Eter,
It is possible to automatically printed output number of decimal; which are reduced.