def test_several_lengths(self):
prng = SHAKE128.new().update(b('Test'))
for length in range(1, 100):
base = Integer.from_bytes(prng.read(length))
modulus2 = Integer.from_bytes(prng.read(length)) | 1
exponent2 = Integer.from_bytes(prng.read(length))
expected = pow(base, exponent2, modulus2)
result = monty_pow(base, exponent2, modulus2)
self.assertEqual(result, expected)
def test_several_lengths(self):
prng = SHAKE128.new().update(b('Test'))
for length in range(1, 100):
base = Integer.from_bytes(prng.read(length))
modulus2 = Integer.from_bytes(prng.read(length)) | 1
exponent2 = Integer.from_bytes(prng.read(length))
expected = pow(base, exponent2, modulus2)
result = monty_pow(base, exponent2, modulus2)
self.assertEqual(result, expected)
def new_test(self, data=data, result=tv.md):
hobj = SHAKE128.new(data=data)
digest = hobj.read(len(result))
self.assertEqual(digest, result)
def get_tag_random(tag, length):
return SHAKE128.new(data=tobytes(tag)).read(length)
def get_fixed_prng():
return SHAKE128.new().update(b"SEED").read
def get_tag_random(tag, length):
return SHAKE128.new(data=tobytes(tag)).read(length)
def create_rng(tag):
rng = StrongRandom(SHAKE128.new(data=tag))
return rng
def create_rng(tag):
rng = StrongRandom(SHAKE128.new(data=tag))
return rng
def new_test(self, data=data, result=tv.md):
hobj = SHAKE128.new(data=data)
digest = hobj.read(len(result))
self.assertEqual(digest, result)
def get_fixed_prng():
return SHAKE128.new().update(b("SEED")).read
#
# The image size is 640x480. My PS3 Eye cam only hase 1 byte per pixel
# of color depth, which is 307,200 bytes per frame.
#
# The raw entropy of each frame, with the camera cooled to 20 degrees
# Celsius and no light entering the lens, is about 0.11 bits per byte,
# +/- 0.02 bits per byte. This provides about 33,792-bits of entropy
# per frame, or 4,224 bytes per frame.
#
# The security margin of SHAKE128 is the min(d/2, 128), where "d" is
# our digest. So by outputting 4096 bytes, my collision security margin
# is between 128-bits to 32,768-bits with SHAKE128. Preimage and 2nd
# preimage collision resistance will have the full 4,096 bytes.
#
# The XOF hashes all 307,200 bytes but outputs a conservative 4 KB.
shake = SHAKE128.new(data=key)
shake.update(bytes(frame))
digest = shake.read(32 + 4096) # 32-byte key, 4096-byte output
# Fast key erasure - https://blog.cr.yp.to/20170723-random.html
# Ensures that if two frames are ever exactly identical, they will be
# keyed differently, ensuring unique outputs
key = digest[:32]
data = digest[32:]
cv2.imshow('webcam noise', frame)
if cv2.waitKey(1) & 0xff == 27:
break
fifo.write(data)
fifo.flush()
#
# The image size is 640x480. My PS3 Eye cam only hase 1 byte per pixel
# of color depth, which is 307,200 bytes per frame.
#
# The raw entropy of each frame, with the camera cooled to 20 degrees
# Celsius and no light entering the lens, is about 0.11 bits per byte,
# +/- 0.02 bits per byte. This provides about 33,792-bits of entropy
# per frame, or 4,224 bytes per frame.
#
# The security margin of SHAKE128 is the min(d/2, 128), where "d" is
# our digest. So by outputting 4096 bytes, my collision security margin
# is between 128-bits to 32,768-bits with SHAKE128. Preimage and 2nd
# preimage collision resistance will have the full 4,096 bytes.
#
# The XOF hashes all 307,200 bytes but outputs a conservative 4 KB.
shake = SHAKE128.new(data=key)
shake.update(bytes(frame))
digest = shake.read(32+4096) # 32-byte key, 4096-byte output
# Fast key erasure - https://blog.cr.yp.to/20170723-random.html
# Ensures that if two frames are ever exactly identical, they will be
# keyed differently, ensuring unique outputs
key = digest[:32]
data = digest[32:]
cv2.imshow('webcam noise', frame)
if cv2.waitKey(1) & 0xff == 27:
break
fifo.write(data)
fifo.flush()
