def standard(miners_number=20, days=10):
# Convert simulation days to seconds
simulation_time = moment.get_seconds(days)
try:
clear_db()
except ConnectionError:
return -1
# Store in redis the simulation event names
configure_event_names([
Miner.BLOCK_REQUEST, Miner.BLOCK_RESPONSE, Miner.BLOCK_NEW,
Miner.HEAD_NEW
])
# Create simpy environment
env = simpy.Environment()
store = simpy.FilterStore(env)
# Create the seed block
seed_block = Block(None, 0, env.now, -1, 0, 1)
hashrates = numpy.random.dirichlet(numpy.ones(miners_number), size=1)
# Create miners
miners = []
# This dict is used to store the connections between miners, so they are not created twice
connections = dict()
for i in range(0, miners_number):
miner = Miner(env, store, hashrates[0, i] * Miner.BLOCK_RATE,
Miner.VERIFY_RATE, seed_block)
miners.append(miner)
connections[miner] = dict()
# Randomly connect miners
for i, miner in enumerate(miners):
miner_connections = numpy.random.choice([True, False],
miners_number)
for j, miner_connection in enumerate(miner_connections):
# Onlye create connection if miner is not self and connection does not already exist
if i != j and miner_connection == True and j not in connections[
miner] and i not in connections[miners[j]]:
# Store connection so its not created twice
connections[miner][j] = True
connections[miners[j]][i] = True
Miner.connect(miner, miners[j])
for miner in miners:
miner.start()
start = time.time()
# Start simulation until limit. Time unit is seconds
env.run(until=simulation_time)
end = time.time()
print("Simulation took: %1.4f seconds" % (end - start))
# Store in redis simulation days
store_days(days)
# After simulation store every miner head, so their chain can be built again
for miner in miners:
r.hset("miners:" + repr(miner.id), "head", miner.chain_head)
# Notify simulation ended
r.publish(Simulator.PUBSUB_CHANNEL, Simulator.SIMULATION_ENDED)
return 0
def mixed_spv_attack(alpha=0.5, beta=0.5, days=10, target_confirmations=3, tSPV=0.5):
print("alpha - {}, beta = {}, days - {}, tgt - {}, tSPV - {}".format(
alpha,
beta,
days,
target_confirmations,
tSPV))
if (alpha + beta > 1.0): raise ValueError("Invalid power fractions")
# Convert simulation days to seconds
simulation_time = moment.get_seconds(days)
try:
clear_db()
except ConnectionError:
return -1
# Store in redis the simulation event names
configure_event_names([
Miner.BLOCK_REQUEST,
Miner.BLOCK_RESPONSE,
Miner.BLOCK_NEW,
Miner.HEAD_NEW,
AttackMiner.WIN,
AttackMiner.LOSE
])
# Create simpy environment
env = simpy.Environment()
store = simpy.FilterStore(env)
# Create the seed block
seed_block = Block(None, 0, env.now, -1, 'seed', 0, 1)
# Create miners
miners = []
# This dict is used to store the connections between miners, so they are not created twice
honest_miner = HonestMiner(env, store, beta * Miner.BLOCK_RATE, Miner.VERIFY_RATE, seed_block)
attack_miner = AttackMiner(env, store, alpha * Miner.BLOCK_RATE, Miner.VERIFY_RATE, seed_block, target_confirmations)
miners = [honest_miner, attack_miner]
other_agents = [honest_miner]
Miner.connect(honest_miner, attack_miner)
if alpha + beta < 1.0:
# fraction of normal validation time to spend
spv_miner = SPVMiner(env, store, (1.0 - alpha - beta) * Miner.BLOCK_RATE, Miner.VERIFY_RATE, seed_block, tSPV)
miners.append(spv_miner)
other_agents.append(spv_miner)
Miner.connect(honest_miner, spv_miner)
Miner.connect(attack_miner, spv_miner)
attack_miner.set_agents(other_agents)
print('miner powers: [honest, attack, (spv)]: {}'.format(list(map(lambda x: x.hashrate, miners))))
for miner in miners: miner.start()
start = time.time()
# Start simulation until limit. Time unit is seconds
env.run(until=simulation_time)
end = time.time()
if Simulator.LOGGING_MODE == "debug":
print("Simulation took: %1.4f seconds" % (end - start))
print(attack_miner.wins, attack_miner.loses)
# Store in redis simulation days
store_days(days)
# for miner in miners: print(miner.name, miner.blocks[miner.chain_head].height, miner.chain_head)
# After simulation store every miner head, so their chain can be built again
for miner in miners: r.hset("miners:" + repr(miner.id), "head", miner.chain_head)
# Notify simulation ended
r.publish(Simulator.PUBSUB_CHANNEL, Simulator.SIMULATION_ENDED)
return (attack_miner.wins, attack_miner.loses)
