def reduce_p(f, p, output=True):
f = process(f)
if any(type(c) != int for c in f.coef) or f.coef[-1] % p == 0:
return "cannot apply"
F = Zn(p)
g = polynom(f.coef, True, F)
print(g)
if f.deg() == 2 or f.deg() == 3:
for i in range(0, p):
if output:
print("g(%s) = %s" %(F(i), g(F(i))))
if g(F(i)) == 0:
return "inconclusive"
return "irreducible"
else:
for i in range(0, p):
if output:
print("g(%s) = %s" %(F(i), g(F(i))))
if g(F(i)) == 0:
return "inconclusive"
for i in range(2, math.ceil((len(g.coef))/2)):
for fn in itertools.product(*[[F(i) for i in range(0, p)] for q in range(0, i+1)]):
if fn == tuple([F(0) for i in range(0, i+1)]) or fn[-1] == F(0):
continue
h = polynom(list(fn), True, F)
temp = divmod(g, h)
if output:
print("%s = (%s)(%s) + (%s)" %(g, h, temp[0], temp[1]))
if not temp[1]:
return "inconclusive"
return "irreducible"
def generate_test_functions():
from random import randint
m = randint(10, 30)
n = randint(2, m)
f = polynom([randint(1, 10)] + [randint(-30, 30) for i in range(0, m)])
g = polynom([randint(1, 10)] + [randint(-30, 30) for i in range(0, n)])
return (f, g)
def karatsuba(a, b):
if type(a) == int and type(b) == int:
n = max(int_len(a), int_len(b))
m = int(n/2)
base = 10
basem = base**m
a1 = int(a/basem)
a0 = a%basem
b1 = int(b/basem)
b0 = b%basem
z2 = a1*b1
z0 = a0*b0
z1 = (a1 + a0)*(b1 + b0) - z2 - z0
return z2*(base**(2*m)) + z1*basem + z0
if type(a) == polynom and type(b) == polynom:
if not len(a) or not len(b):
return polynom(0)
n = max(len(a), len(b))
m = int(n/2)
a1 = a >> m
a0 = polynom(a.coef[0:m], True, a.ring)
b1 = b >> m
b0 = polynom(b.coef[0:m], True, b.ring)
z2 = a1*b1
z0 = a0*b0
z1 = (a1 + a0)*(b1 + b0) - z2 - z0
return (z2 << 2*m) + (z1 << m) + z0
def ExpandKey(self):
result = self.keys[0]
temp = result[-1]
for i in range(4):
if i % 4 == 0:
temp = self.ShiftRows(['', temp])[1]
temp = self.SubBytes([temp])[0]
if self.Rcon == False:
self.Rcon = polynom('1')
else:
self.Rcon *= polynom('10')
if self.Rcon()[1] >= 0x80:
self.Rcon += polynom(bin(0x11b)[2:])
tmp = int(self.Rcon()[2], 16) ^ int(temp[0], 16)
temp = [hex(tmp)[2:]] + temp[1:]
tmp1 = []
for j in range(4):
tmp2 = hex(int(temp[j], 16) ^ int(result[i][j], 16))[2:]
tmp1 += ["0" * ((2 - len(tmp2)) % 2) + tmp2]
result += [tmp1]
temp = tmp1
keys = []
for i in range(len(result) // 4):
keys += [result[4 * i:4 * (i + 1)]]
return keys
def AddRoundKey(self, mat):
result = mat[:]
key = self.TransposeMat(self.keys[0])
for i in range(len(mat)):
for j in range(len(mat[i])):
tmp = (polynom(bin(int(result[i][j], 16))[2:]) +
polynom(bin(int(key[i][j], 16))[2:]))()[2]
result[i][j] = "0" * ((2 - len(tmp)) % 2) + tmp
self.keys = self.ExpandKey()
self.keys = self.keys[1:]
return mat
def mix(self, line):
if len(line) != 4:
return False
result = []
mat = [['02', '03', '01', '01'], ['01', '02', '03', '01'],
['01', '01', '02', '03'], ['03', '01', '01', '02']]
for i in range(4):
tmp = polynom('0')
for j in range(4):
tmp += polynom(bin(int(mat[i][j]))[2:]) * polynom(
bin(int(line[j], 16))[2:])
result += ["0" * ((2 - len(tmp()[2])) % 2) + tmp()[2]]
return result
def divp(a, b):
if a.deg() < b.deg():
raise Exception("a has to have degree greater than or equal to b's.")
if a.ring != b.ring:
raise Exception("a and b have to be polynomials over the same ring.")
print("$a(x) =", a, "$")
print("$b(x) =", b, "$")
l_num = max([abs(coef) for coef in a.coef + b.coef])
l = floor(log(abs(l_num))) + 1
#print("$l$ is the number of digits in $", l_num, "$, which is ", l)
q = []
ap = a
c = b.coef[-1]
m = ap.deg()
n = b.deg()
powers = [1, c]
for i in range(2, m-n+1):
powers.append(powers[-1]*c)
loop_num = 1
while m >= n:
ap_norm = max([abs(coef) for coef in ap.coef])
l_ap = floor(log(abs(ap_norm))) + 1
#print("At the beginning of the %sth iteration through the loop, $\\norm[\\infty]{a^\\prime} =" %(loop_num), ap_norm, "$, with number of digits $", l_ap, "$ and it is", l_ap <= loop_num*l, "that $L(\\norm[\\infty]{a^\\prime})$ is $\O(il)$")
#print("Also, $a^\\prime =", ap, "$")
#print("And so far, $q =", polynom(q, ring=a.ring), "$")
d = ap.coef[-1]*powers[m-n]
#print("So $d =", d, "$")
q.append(d)
ap = c*ap - ap.coef[-1]*(b << m-n) # This is b * x^{m-n}, I implemented multiplying by x^n as polynom << n.
for i in range(1, min(m - ap.deg() - 1, m - n) + 1):
q.append(0)
ap = c*ap
m = ap.deg()
loop_num += 1
q = polynom(q, ring=a.ring)
r = ap
#print("Finally, we are left with $q =", q, "$ and $r =", r, "$")
return (q, r)
def mod_gcd2(a, b):
if a.ring != int or b.ring != int:
return "Nope"
print("Step (1)")
cont_a = gcd(*a.coef)
cont_b = gcd(*b.coef)
a = a / cont_a
b = b / cont_b
cont_gcd = gcd(cont_a, cont_b)
print(cont_gcd)
d = gcd(a.coef[-1], b.coef[-1])
M = LandauMignotte(a, b)
print("d =", d)
print("M =", M)
primes = sieve_eratosthenes(int(M+1))
prime_index = 0
while True:
print("Step (2)")
while (a.coef[-1] % primes[prime_index] == 0 and b.coef[-1] % primes[prime_index] == 0):
prime_index += 1
p = primes[prime_index]
prime_index += 1
c_p = gcd(a.change_ring(Zn(p)), b.change_ring(Zn(p)))
c_p = c_p*~c_p.coef[-1]
g_p = (d % p)*c_p
print("with p =", p, "g_p =", g_p)
while True:
print("Step (3)")
if g_p.deg() == 0:
return polynom([1])
P = p
g = g_p
print("P =", P, "and g =", g)
print("Step (4)")
while P <= M:
print("P =", P)
while (a.coef[-1] % primes[prime_index] == 0 or b.coef[-1] % primes[prime_index] == 0):
prime_index += 1
p = primes[prime_index]
prime_index += 1
c_p = gcd(a.change_ring(Zn(p)), b.change_ring(Zn(p)))
c_p = c_p*~c_p.coef[-1]
g_p = (d % p)*c_p
print("with p =", p, "g_p =", g_p)
if g_p.deg() < g.deg():
print("New g_p has lower degree than the previous one.")
break
if g_p.deg() == g.deg():
print("Degrees match when p =", p)
g = polynom([CRA2(g.coef[i], g_p.coef[i], P, p) for i in range(0, len(g.coef))], True)
P *= p
print("g =", g)
else:
print("P =", P, "> M =", M, "so time to test for completion with g =", g)
if any(coef > M for coef in g.coef):
print("Positive coefficients are too large - we must have negative coefficients.")
coefs = []
for coef in g.coef:
if coef > M:
coefs.append(coef - P)
else:
coefs.append(coef)
alt_g = polynom(coefs, True)
if gcd(*alt_g.coef) != 1:
alt_g = alt_g/gcd(*alt_g.coef)
print("Primitive part =", alt_g)
if not a % alt_g and not b % alt_g:
return cont_gcd*alt_g
else:
if gcd(*g.coef) != 1:
g = g/gcd(*g.coef)
print("Primitive part =", g)
if not a % g and not b % g:
return cont_gcd*g
break
