def request_agreement(self):
"""7. Alice starts key agreement
generate fingerprint and doing fuzzy commitment
send hash and delta to Bob
"""
log.info('7. Alice starts key agreement')
#===============================================================================
# Fingerprinting and Fuzzy Cryptography
#===============================================================================
# generate fingerprint
self.fingerprint = fingerprint_energy_diff.get_fingerprint(self.recording_data, self.recording_samplerate)
# save fingerprint for debugging
scipy.savetxt("client_fingerprint.txt", self.fingerprint)
log.debug('Alice fingerprint:\n'+str(self.fingerprint))
# doing commit, rs codes can correct up to (n-m)/2 errors
self.hash, self.delta, self.private_key = crypto_fuzzy_jw.JW_commit(self.fingerprint, m=self.rs_code_m, n=self.rs_code_n, symsize=self.rs_code_symsize)
log.debug('Alice Blob:\nHash:\n'+str(self.hash)+'\nDelta:\n'+str(self.delta))
# save delta for debugging
scipy.savetxt("client_delta.txt", self.delta)
# remote call for key agreement
# using debug means sending also the fingerprint in clear text!!!
# meaning no security!
if self.debug:
accept_agreement = self.pairing_server.callRemote("agreement_debug", self.fingerprint.tolist(), self.hash, self.delta.tolist())
accept_agreement.addCallbacks(self.answer_agreement)
else:
accept_agreement = self.pairing_server.callRemote("agreement", self.hash, self.delta.tolist())
accept_agreement.addCallbacks(self.answer_agreement)
def get_possible_fingerprints(recording_data, recording_samplerate):
"""generate many fingerprints varying in time
:param recording_data: complete recording data
:param recording_samplerate: samplerate of recording
:return: many fingerprints
"""
fingerprint = fingerprint_energy_diff.get_fingerprint(recording_data, recording_samplerate)
possible_fingerprints = [fingerprint]
# correct 0,20 seconds in time (0,20*44100=~8800) -> 88*100 data chunks!
n = 176 # -> 0,4 seconds
for i in range(1, n):
log.debug('Generating possible fingerprint '+str(i)+' of '+str(n))
# move 100 data chunks to left and build fingerprint
data_left = move_data_left(recording_data, i)
possible_fingerprints += [fingerprint_energy_diff.get_fingerprint(data_left, recording_samplerate)]
# move 100 data chunks to right and build fingerprint
data_right = move_data_right(recording_data, i)
possible_fingerprints += [fingerprint_energy_diff.get_fingerprint(data_right, recording_samplerate)]
return possible_fingerprints
def remote_agreement_debug(self, fingerprint_debug, hash, delta):
"""THIS IS A DEBUG FUNCTION
using the fingerprint from the client
Using this means NO security!
8. Key Agreement on Server
generates fingerprint and decommits
using received ``hash`` and ``delta``
:param hash: SHA-512 Hash of codeword c
:type hash: str
:param delta: difference
:type delta: list
"""
log.info('8. Key Agreement on Server')
#===============================================================================
# Fingerprinting and Fuzzy Cryptography
#===============================================================================
# generate fingerprint, not used see possible fingerprints
self.fingerprint = fingerprint_energy_diff.get_fingerprint(self.recording_data, self.recording_samplerate)
# save fingerprint for debugging
scipy.savetxt("server_fingerprint.txt", self.fingerprint)
log.debug('Bob fingerprint:\n'+str(self.fingerprint))
# get possible fingerprints
possible_fingerprints = get_possible_fingerprints(self.recording_data, self.recording_samplerate)
# DEBUG
length = len(fingerprint_debug)
distances = []
for fingerprint in possible_fingerprints:
# calculate hamming distance between fingerprints
distance = hamming_distance(fingerprint, fingerprint_debug)
print('Distance: '+str(distance)+' of '+str(length))
print('Correlation percentage: '+str(1-float(distance)/float(length)))
distances += [distance]
min_distance = min(distances)
min_correlation = 1-float(min(distances))/float(length)
print('Minimal distance: '+str(min_distance)+' of '+str(length))
print('Minimal correlation percentage: '+str(min_correlation))
try:
minimals = scipy.genfromtxt(self.debug_file)
except Exception, err:
log.error('%s' % str(err))
print('first time, so creating minimals')
minimals = scipy.array([])
def remote_agreement(self, hash, delta):
"""8. Key Agreement on Server
generates fingerprint and decommits
using received ``hash`` and ``delta``
:param hash: SHA-512 Hash of codeword c
:type hash: str
:param delta: difference
:type delta: list
"""
log.info('8. Key Agreement on Server')
#===============================================================================
# Fingerprinting and Fuzzy Cryptography
#===============================================================================
# generate fingerprint, not used see possible fingerprints
self.fingerprint = fingerprint_energy_diff.get_fingerprint(self.recording_data, self.recording_samplerate)
# save fingerprint for debugging
scipy.savetxt("server_fingerprint.txt", self.fingerprint)
log.debug('Bob fingerprint:\n'+str(self.fingerprint))
# get possible fingerprints
possible_fingerprints = get_possible_fingerprints(self.recording_data, self.recording_samplerate)
for fingerprint in possible_fingerprints:
try:
# trying to decommit
self.private_key, corr = crypto_fuzzy_jw.JW_decommit(hash, delta, fingerprint, m=self.rs_code_m, n=self.rs_code_n, symsize=self.rs_code_symsize)
except Exception, err:
log.error('%s' % str(err))
else:
# if hash is the same accept key agreement,
# test is in JW_decommit, try fails when not!
# return True for accepted connection
return True
# fingerprinting based on energy difference
import fingerprint_energy_diff
import logging
# Logging all above INFO level, output to stderr
logging.basicConfig(#format='%(asctime)s %(levelname)-8s %(message)s')
format='%(levelname)-8s %(message)s')
log = logging.getLogger("fuzzy_pairing")
log.setLevel(logging.DEBUG)
# load channels:
left_channel, samplerate = load_mono(base+'1.5_3/high/music5.wav')
right_channel, samplerate = load_mono(base+'1.5_3/high/music1.wav')
# fingerprint energy diff
fingerprint_left = fingerprint_energy_diff.get_fingerprint(left_channel, samplerate)
fingerprint_right = fingerprint_energy_diff.get_fingerprint(right_channel, samplerate)
print repr(fingerprint_left)
print repr(fingerprint_right)
# calculate hamming distance between fingerprints
distance = hamming_distance(fingerprint_left, fingerprint_right)
length = len(fingerprint_left)
print length, distance
print('Correlation %: '+str(1-float(distance)/float(length)))
path = "/home/ds1/Projekte/Fuzzy Pairing Paper/Versuche Audiodateien/"
matrix = list()
# get all files in all subdirectories etc.
for root, dirs, files in os.walk(path):
for name in files:
filename = os.path.join(root, name)
print filename
print "current file is: " + name
mono_channel, samplerate = load_mono(filename)
# fingerprint energy diff
fingerprint = fingerprint_energy_diff.get_fingerprint(mono_channel, samplerate)
# you can add more analysis using helper_analysis here
# and write the results in the matrix for further analyzing
matrix.append([filename,fingerprint])
print matrix
# save it with pickle, can later be analyzed
with file('analysis_matrix.txt', 'wr') as f:
pickle.dump(matrix, f)