research-lab/source-code/MiniNero/LLW_Sigs.py
2016-02-05 13:20:44 -07:00

55 lines
1.9 KiB
Python

#see mrl_notes .. obv this is a work in progress
import MiniNero
import PaperWallet
def keyImage(x):
HP = MiniNero.hashToPoint_ct(MiniNero.scalarmultBase(x))
return MiniNero.scalarmultKey(HP, x)
def LLW_Sig(pk, xx, index ):
n = len(pk)
print("Generating LLW sig of length ", n)
L = [None] * n
R = [None] * n
c= [None] * n
s = [PaperWallet.skGen() for i in range(0, n)]
HP = [MiniNero.hashToPoint_ct(i) for i in pk]
pj = ''.join(pk)
keyimage = keyImage(xx) #ok
s[index] = MiniNero.mul_8(s[index])
L[index] = MiniNero.scalarmultBase(s[index])
R[index] = MiniNero.scalarmultKey(HP[index], s[index]) #aH
j = (index + 1) % n
c[j] = MiniNero.cn_fast_hash(pj+L[index]+R[index])
while j != index:
L[j] = MiniNero.addKeys(MiniNero.scalarmultBase(s[j]), MiniNero.scalarmultKey(pk[j], c[j])) #Lj = sG + cxG
R[j] = MiniNero.addKeys(MiniNero.scalarmultKey(HP[j], s[j]), MiniNero.scalarmultKey(keyimage, c[j])) #Rj = sH + cxH
cj = (j + 1) % n
c[cj] = MiniNero.cn_fast_hash(pj + L[j] + R[j]) #c j+1 = H(pk + Lj + Rj
j = cj #increment j
s[index] = MiniNero.sc_mulsub_keys(s[index], c[index], xx) #si = a - c x so a = s + c x
print("sigma = ", keyimage, c[0], s[:])
return keyimage, c[0], s[:]
def LLW_Ver(pk, keyimage, c1, s):
n= len(pk) #ok
print("verifying LLW sig of length", n)
L = [None]*n
R = [None]*n
c= [None]*(n+1)
pj = ''.join(pk)
HP = [MiniNero.hashToPoint_ct(i) for i in pk]
c[0] = c1
j = 0
while j < n:
L[j] = MiniNero.addKeys(MiniNero.scalarmultBase(s[j]), MiniNero.scalarmultKey(pk[j], c[j]))
R[j] = MiniNero.addKeys(MiniNero.scalarmultKey(HP[j], s[j]), MiniNero.scalarmultKey(keyimage, c[j]))
cj = j + 1
c[cj] = MiniNero.cn_fast_hash(pj + L[j] + R[j])
j = cj
rv = (c[0] == c[n])
print("sig verifies complete", rv)
print("c", c)
print("L", L)
print("R", R)
return rv