Post
Topic
Board Development & Technical Discussion
Re: Pollard's kangaroo ECDLP solver
by
COBRAS
on 13/06/2020, 14:17:26 UTC

Please, someone make a scrypt for automatic shifting pubkey to "zero" ? I was try many times and not found any keys I think because of this. Manualy shift all pubkeys to "zero" is f**ing work, trust me please.

i don`t know for what you need shift pub key but any way here is python code and you can launch this code online https://repl.it/languages/python3

Code:


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)



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

#CHANGE HERE beginrange and pointstr
beginrange=0x80000000000000000000
pointstr = '037e1238f7b1ce757df94faa9a2eb261bf0aeb9f84dbf81212104e78931c2a19dc'

pt= getuncompressedpub(pointstr)
(subptx,subpty) = ptmul(g, beginrange, p)
result=addpt(pt, (subptx,p-subpty), p)
print("shifted result> 04%064x%064x"%result)

Code have all functions that you need to work with points.

Than you for your help Etar.

I think with shifter ranges difficult of calculus will be not 2^256 but in ex. 2^256-2^200 for 56 bytes key.

And if no key in 56 range need go next, but, if no key  in 256 range this will be understand only after 256 Byts calculus VS 56 bytes.

Buddy, code what you give, is shifted pubkey to zero, or not ? I thin sghift key to zero mean what from pubkey deducted a range, or I mistaken in this ?