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264 lines
7.6 KiB
Python

import time
from typing import List
import numpy as np
from concrete import fhe
CHUNK_SIZE = 4
KEY_SIZE = 32
VALUE_SIZE = 32
assert KEY_SIZE % CHUNK_SIZE == 0
assert VALUE_SIZE % CHUNK_SIZE == 0
NUMBER_OF_KEY_CHUNKS = KEY_SIZE // CHUNK_SIZE
NUMBER_OF_VALUE_CHUNKS = VALUE_SIZE // CHUNK_SIZE
def encode(number, width):
binary_repr = np.binary_repr(number, width=width)
blocks = [binary_repr[i : (i + CHUNK_SIZE)] for i in range(0, len(binary_repr), CHUNK_SIZE)]
return np.array([int(block, 2) for block in blocks])
def encode_key(number):
return encode(number, width=KEY_SIZE)
def encode_value(number):
return encode(number, width=VALUE_SIZE)
def decode(encoded_number):
result = 0
for i in range(len(encoded_number)):
result += 2 ** (CHUNK_SIZE * i) * encoded_number[(len(encoded_number) - i) - 1]
return result
keep_if_match_lut = fhe.LookupTable([0 for _ in range(16)] + [i for i in range(16)])
keep_if_no_match_lut = fhe.LookupTable([i for i in range(16)] + [0 for _ in range(16)])
def _replace_impl(key, value, candidate_key, candidate_value):
number_of_matching_chunks = np.sum((candidate_key - key) == 0)
fhe.hint(number_of_matching_chunks, can_store=NUMBER_OF_KEY_CHUNKS)
match = number_of_matching_chunks == NUMBER_OF_KEY_CHUNKS
packed_match_and_value = (2**CHUNK_SIZE) * match + value
value_if_match_else_zeros = keep_if_match_lut[packed_match_and_value]
packed_match_and_candidate_value = (2**CHUNK_SIZE) * match + candidate_value
zeros_if_match_else_candidate_value = keep_if_no_match_lut[packed_match_and_candidate_value]
return value_if_match_else_zeros + zeros_if_match_else_candidate_value
def _query_impl(key, candidate_key, candidate_value):
number_of_matching_chunks = np.sum((candidate_key - key) == 0)
fhe.hint(number_of_matching_chunks, can_store=NUMBER_OF_KEY_CHUNKS)
match = number_of_matching_chunks == NUMBER_OF_KEY_CHUNKS
packed_match_and_candidate_value = (2**CHUNK_SIZE) * match + candidate_value
candidate_value_if_match_else_zeros = keep_if_match_lut[packed_match_and_candidate_value]
return fhe.array([match, *candidate_value_if_match_else_zeros])
class KeyValueDatabase:
_state: List[np.ndarray]
_replace_circuit: fhe.Circuit
_query_circuit: fhe.Circuit
def __init__(self):
self._state = []
configuration = fhe.Configuration(
enable_unsafe_features=True,
use_insecure_key_cache=True,
insecure_key_cache_location=".keys",
)
replace_compiler = fhe.Compiler(
_replace_impl,
{
"key": "encrypted",
"value": "encrypted",
"candidate_key": "encrypted",
"candidate_value": "encrypted",
},
)
query_compiler = fhe.Compiler(
_query_impl,
{
"key": "encrypted",
"candidate_key": "encrypted",
"candidate_value": "encrypted",
},
)
replace_inputset = [
(
# key
np.ones(NUMBER_OF_KEY_CHUNKS, dtype=np.int64) * (2**CHUNK_SIZE - 1),
# value
np.ones(NUMBER_OF_VALUE_CHUNKS, dtype=np.int64) * (2**CHUNK_SIZE - 1),
# candidate_key
np.ones(NUMBER_OF_KEY_CHUNKS, dtype=np.int64) * (2**CHUNK_SIZE - 1),
# candidate_value
np.ones(NUMBER_OF_VALUE_CHUNKS, dtype=np.int64) * (2**CHUNK_SIZE - 1),
)
]
query_inputset = [
(
# key
np.ones(NUMBER_OF_KEY_CHUNKS, dtype=np.int64) * (2**CHUNK_SIZE - 1),
# candidate_key
np.ones(NUMBER_OF_KEY_CHUNKS, dtype=np.int64) * (2**CHUNK_SIZE - 1),
# candidate_value
np.ones(NUMBER_OF_VALUE_CHUNKS, dtype=np.int64) * (2**CHUNK_SIZE - 1),
)
]
print()
print("Compiling replacement circuit...")
start = time.time()
self._replace_circuit = replace_compiler.compile(replace_inputset, configuration)
end = time.time()
print(f"(took {end - start:.3f} seconds)")
print()
print("Compiling query circuit...")
start = time.time()
self._query_circuit = query_compiler.compile(query_inputset, configuration)
end = time.time()
print(f"(took {end - start:.3f} seconds)")
print()
print("Generating replacement keys...")
start = time.time()
self._replace_circuit.keygen()
end = time.time()
print(f"(took {end - start:.3f} seconds)")
print()
print("Generating query keys...")
start = time.time()
self._query_circuit.keygen()
end = time.time()
print(f"(took {end - start:.3f} seconds)")
def insert(self, key, value):
print()
print("Inserting...")
start = time.time()
self._state.append([encode_key(key), encode_value(value)])
end = time.time()
print(f"(took {end - start:.3f} seconds)")
def replace(self, key, value):
print()
print("Replacing...")
start = time.time()
encoded_key = encode_key(key)
encoded_value = encode_value(value)
for entry in self._state:
entry[1] = self._replace_circuit.encrypt_run_decrypt(encoded_key, encoded_value, *entry)
end = time.time()
print(f"(took {end - start:.3f} seconds)")
def query(self, key):
print()
print("Querying...")
start = time.time()
encoded_key = encode_key(key)
accumulation = np.zeros(1 + NUMBER_OF_VALUE_CHUNKS, dtype=np.int64)
for entry in self._state:
contribution = self._query_circuit.encrypt_run_decrypt(encoded_key, *entry)
accumulation += contribution
match_count = accumulation[0]
if match_count > 1:
message = "Key inserted multiple times"
raise RuntimeError(message)
result = decode(accumulation[1:]) if match_count == 1 else None
end = time.time()
print(f"(took {end - start:.3f} seconds)")
return result
db = KeyValueDatabase()
# Test: Insert/Query
db.insert(3, 4)
assert db.query(3) == 4
db.replace(3, 1)
assert db.query(3) == 1
# Test: Insert/Query
db.insert(25, 40)
assert db.query(25) == 40
# Test: Query Not Found
assert db.query(4) is None
# Test: Replace/Query
db.replace(3, 5)
assert db.query(3) == 5
# Define lower/upper bounds for the key
minimum_key = 0
maximum_key = 2**KEY_SIZE - 1
# Define lower/upper bounds for the value
minimum_value = 0
maximum_value = 2**VALUE_SIZE - 1
# Test: Insert/Replace/Query Bounds
# Insert (key: minimum_key , value: minimum_value) into the database
db.insert(minimum_key, minimum_value)
# Query the database for the key=minimum_key
# The value minimum_value should be returned
assert db.query(minimum_key) == minimum_value
# Insert (key: maximum_key , value: maximum_value) into the database
db.insert(maximum_key, maximum_value)
# Query the database for the key=maximum_key
# The value maximum_value should be returned
assert db.query(maximum_key) == maximum_value
# Replace the value of key=minimum_key with maximum_value
db.replace(minimum_key, maximum_value)
# Query the database for the key=minimum_key
# The value maximum_value should be returned
assert db.query(minimum_key) == maximum_value
# Replace the value of key=maximum_key with minimum_value
db.replace(maximum_key, minimum_value)
# Query the database for the key=maximum_key
# The value minimum_value should be returned
assert db.query(maximum_key) == minimum_value