84 lines
2.5 KiB
Python
84 lines
2.5 KiB
Python
"""High level Verifiable Delay Function using keccak (sha3)."""
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from hashlib import sha3_256
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from typing import Union
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import time
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from statistics import mean
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from math import ceil
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from .mimc import forward_mimc, reverse_mimc, is_fast
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"""
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Kevin Froman 2020
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>.
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"""
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DEFAULT_ROUNDS = 8000
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def _sha3_256_hash(data: bytes) -> bytes:
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sha3 = sha3_256()
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sha3.update(data)
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return sha3.digest()
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def vdf_create(data: bytes, rounds: int = DEFAULT_ROUNDS, dec=False) -> str:
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assert rounds > 1
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input_data: int = _sha3_256_hash(data)
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if dec:
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return int.from_bytes(reverse_mimc(input_data, rounds), "big")
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return reverse_mimc(input_data, rounds).hex()
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def vdf_verify(
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data: bytes,
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test_hash: str,
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rounds: int = DEFAULT_ROUNDS) -> bool:
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"""Verify data for test_hash generated by vdf_create."""
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assert rounds > 1
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should_match = _sha3_256_hash(data).lstrip(b'\0')
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if isinstance(test_hash, int):
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test_hash = test_hash.to_bytes((test_hash.bit_length() + 7) // 8, "big")
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else:
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try:
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test_hash = bytes.fromhex(test_hash)
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except ValueError:
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return False
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return forward_mimc(test_hash, rounds) == should_match
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def profile_cpu_speed(seconds=1) -> float:
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n = 2
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start = time.time()
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done = False
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results = []
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try:
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for _ in range(20):
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done = False
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n = 2
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start = time.time()
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while not done:
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vdf_create(b't', n)
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if time.time() - start >= seconds:
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break
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n += 1
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results.append(n)
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except KeyboardInterrupt:
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pass
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return ceil(mean(results))
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if __name__ == "__main__":
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print("Calculate how may rounds are needed for X seconds (influenced by system processes): ")
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seconds = int(input("Seconds: "))
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print("Rounds:", profile_cpu_speed(seconds))
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