Files
tfhe-rs/ci/lattice_estimator.sage
2024-06-20 08:35:37 +02:00

116 lines
4.0 KiB
Python
Executable File

"""
lattice_estimator
-----------------
Test cryptographic parameters set against several attacks to estimate their security level.
"""
import pathlib
import sys
sys.path.insert(1, "lattice-estimator")
from estimator import *
model = RC.MATZOV
# Minimum level of security thresholds for parameters set in bits
SECURITY_LEVEL_THRESHOLD_SOFT = 132
SECURITY_LEVEL_THRESHOLD_HARD = 128
def check_security(filename):
"""
Run lattice estimator to determine if a parameters set is secure or not.
:param filename: name of the file containing parameters set
:return: :class:`list` of parameters to update
"""
filepath = pathlib.Path("ci", filename)
load(filepath)
print(f"Parsing parameters in {filepath}")
to_update = []
to_watch = []
for param in all_params:
if param.tag.startswith("TFHE_LIB_PARAMETERS"):
# This third-party parameters set is known to be less secure, just skip the analysis.
continue
print(f"\t{param.tag}...\t", end="")
is_n_size_too_low = param.n <= 450
is_noise_level_too_low = param.Xe.stddev < 4.0
if is_n_size_too_low:
reason = f"n size is too low {param.n} minimum is 450"
elif is_noise_level_too_low:
reason = f"noise level is too low {round(param.Xe.stddev,3)} minimum is 4.0"
if is_n_size_too_low or is_noise_level_too_low:
print(f"FAIL\t{reason}")
to_update.append((param, reason))
continue
try:
# The lattice estimator is not able to manage such large dimension.
# If we have the security for smaller `n` then we have security for larger ones.
if param.n > 16384:
param = param.updated(n=16384)
usvp_level = LWE.primal_usvp(param, red_cost_model=model)
dual_level = LWE.dual_hybrid(param, red_cost_model=model)
estimator_level = log(min(usvp_level["rop"], dual_level["rop"]), 2).n()
security_level = f"security level = {estimator_level} bits"
if estimator_level < SECURITY_LEVEL_THRESHOLD_HARD:
print(f"FAIL\t({security_level})")
reason = f"attained {security_level} target is {SECURITY_LEVEL_THRESHOLD_HARD} bits"
to_update.append((param, reason))
continue
elif estimator_level < SECURITY_LEVEL_THRESHOLD_SOFT:
print(f"WARNING\t({security_level})")
reason = f"attained {security_level} target is {SECURITY_LEVEL_THRESHOLD_SOFT} bits"
to_watch.append((param, reason))
continue
except Exception as err:
print("FAIL")
to_update.append((param, f"{repr(err)}"))
else:
print(f"OK\t({security_level})")
return to_update, to_watch
if __name__ == "__main__":
params_to_update = []
params_to_watch = []
for params_filename in (
"boolean_parameters_lattice_estimator.sage",
"shortint_classic_parameters_lattice_estimator.sage",
"shortint_multi_bit_parameters_lattice_estimator.sage",
):
to_update, to_watch = check_security(params_filename)
params_to_update.extend(to_update)
params_to_watch.extend(to_watch)
if params_to_watch:
print("Some parameters need attention")
print("------------------------------")
for param, reason in params_to_watch:
print(f"[{param.tag}] reason: {reason} (param: {param})")
if params_to_update:
if params_to_watch:
# Add a visual separator.
print("\n\n ################################### \n\n")
print("Some parameters need update")
print("---------------------------")
for param, reason in params_to_update:
print(f"[{param.tag}] reason: {reason} (param: {param})")
sys.exit(int(1)) # Explicit conversion is needed to make this call work
else:
print("All parameters passed the security check")