def main():
for i in range(p.Runs):
clock = 0 # set clock to 0 at the start of the simulation
if p.hasTrans:
if p.Ttechnique == "Light":
Transaction.create_transactions_light(
) # generate pending transactions
elif p.Ttechnique == "Full":
Transaction.create_transactions_full(
) # generate pending transactions
Node.generate_gensis_block(
) # generate the gensis block for all miners
Scheduler.initial_events() # initiate initial events to start with
while not Queue.isEmpty() and clock <= p.simTime:
next_event = Queue.get_next_event()
clock = next_event.time # move clock to the time of the event
Event.run_event(next_event)
Queue.remove_event(next_event)
Consensus.freshness_preferred(
) # apply the longest chain to resolve the forks
Results.calculate(
) # calculate the simulation results (e.g., block statstics and miners' rewards)
########## reset all global variable before the next run #############
Results.reset() # reset all variables used to calculate the results
Node.resetState(
) # reset all the states (blockchains) for all nodes in the network
print("Percentage of blocks mined by the attacker: ",
(p.attacker_blocks / float(p.Runs)))
def run_event(event): # run the event from the event list
from Scheduler import Scheduler
miner = p.NODES[event.block.miner]
minerId = miner.id
eventTime = event.time
blockDepth = event.block.depth
blockId = event.block.id # block id
blockPrev = event.block.previous # previous block id
blockTime = event.block.timestamp
blockTrans = event.block.transactions
blockSize = event.block.size
##################################### Block Creation Event #######################################################
if event.type == "create_block":
if (blockPrev == miner.last_block().id
and miner.currentMode == "public"):
miner.mined_blocks += 1
Results.totalBlocks += 1 # count # of total blocks created!
if p.hasTrans and p.Ttechnique == "Light":
blockTrans, blockSize = Transaction.execute_transactions_light(
)
elif p.hasTrans and p.Ttechnique == "Full":
blockTrans, blockSize = Transaction.execute_transactions_full(
miner, blockTime)
event.block.transactions = blockTrans
if p.hasUncles:
blockUncles = Node.add_uncles(
miner) # add uncles to the block
event.block.uncles = blockUncles
b = Block(blockDepth, blockId, blockPrev, blockTime, minerId,
blockTrans, blockSize, [])
miner.blockchain.append(b)
if p.hasTrans and p.Ttechnique == "Light":
Transaction.create_transactions_light(
) # generate transactions
#Add the block to the dictionary
miner.network_blocks[event.block.id] = b
miner.longest_branch_length = blockDepth
miner.longest_branches = [blockId]
#Add the block to the list of longest branches
# if(blockDepth > miner.longest_branch_length):
# miner.longest_branch_length = blockDepth
# miner.longest_branches = [blockId]
# elif(blockDepth == miner.longest_branch_length):
# miner.longest_branches += [blockId]
currentTime = eventTime
event.time = blockTime
#Send block to all the other nodes
Scheduler.receive_block_event(event)
miner.check_switch(time=currentTime, blocktime=blockTime)
#attacker in private mode starts building a private block on top of this block
if (miner.currentMode == "private"):
Scheduler.create_private_block_event(miner, currentTime)
if (miner.type == "oracle"):
Scheduler.oracle_attack_end_event(
minerId, blockTime, b)
#node in public mode starts building a regular block
else:
Scheduler.create_block_event(miner, currentTime)
#####
# if(miner.type != "honest"):
# print("mined block ", blockId, " at time ", currentTime, " on ", blockPrev)
##################################### Private Block Creation Event #######################################################
elif event.type == "create_private_block":
if (miner.currentMode == "private"
and miner.privateblockchain != []
and blockPrev == miner.last_private_block().id):
#print("depth of mainchain: ", miner.last_block().depth)
#print("Depth of private chain: ", miner.privateblockchain[len(miner.privateblockchain)-1].depth)
#print("Totalblocks: ", Results.totalBlocks)
miner.mined_blocks += 1
Results.totalBlocks += 1 # count # of total blocks created!
if p.hasTrans and p.Ttechnique == "Light":
blockTrans, blockSize = Transaction.execute_transactions_light(
)
elif p.hasTrans and p.Ttechnique == "Full":
blockTrans, blockSize = Transaction.execute_transactions_full(
miner, blockTime)
event.block.transactions = blockTrans
if p.hasUncles:
blockUncles = Node.add_uncles(
miner) # add uncles to the block
event.block.uncles = blockUncles
b = Block(blockDepth, blockId, blockPrev, blockTime, minerId,
blockTrans, blockSize, [])
miner.privateblockchain.append(b)
if p.hasTrans and p.Ttechnique == "Light":
Transaction.create_transactions_light(
) # generate transactions
miner.network_blocks[event.block.id] = b
currentTime = eventTime
# print("new private block ",blockId, " at ", currentTime)
eventTime = blockTime
miner.check_switch(time=currentTime, blocktime=blockTime)
if (miner.currentMode == "public"):
#publish block if attack becomes successful
#Scheduler.receive_block_event(event)
Scheduler.receive_private_blocks_event(event)
Scheduler.create_block_event(miner, currentTime)
#Add the block to the list of longest branches
miner.longest_branch_length = blockDepth
miner.longest_branches = [blockId]
else:
#Create private block if attack continues
Scheduler.create_private_block_event(miner, currentTime)
#####
# if(miner.type != "honest"):
# print("mined private block ", blockId, " at time ", currentTime, " on ", blockPrev)
##################################### Block Receiving Event #######################################################
elif event.type == "receive_block":
#print(event.node," recieved: ",blockId)
node = p.NODES[event.node] # recipint
node.network_blocks[event.block.id] = event.block
lastBlockId = node.last_block().id # the id of last block
blockUncles = event.block.uncles
# if(node.id == 16):
# print("recieved block ",blockId," mined at ", blockTime," at ",eventTime, "depth: ", blockDepth)
#### case 1: the received block is built on top of the last block according to the recipient's blockchain ####
if blockPrev == lastBlockId:
#Add the block to the list of longest branches
node.longest_branch_length = blockDepth
node.longest_branches = [blockId]
block = Block(blockDepth, blockId, blockPrev, blockTime,
minerId, blockTrans, blockSize,
blockUncles) # construct the block
node.blockchain.append(
block) # append the block to local blockchain
if p.hasTrans and p.Ttechnique == "Full":
Node.update_transactionsPool(node, event.block)
currentTime = eventTime # set the time when to start mining the next block
if (node.type != "honest"):
#If attacker is in public mode, it checks if it can attack
if (node.currentMode == "public"):
node.check_switch(time=currentTime)
if (node.currentMode == "private"):
Scheduler.create_private_block_event(
node, currentTime)
#If attacker is in private mode, it checks if the attack can continue
else:
node.check_switch(time=currentTime)
#If attack unsuccessful, check the possibility of attacking again
if (node.currentMode == "public"):
node.check_switch(time=currentTime)
if (node.currentMode == "private"):
Scheduler.create_private_block_event(
node, currentTime)
if (node.currentMode == "public"):
Scheduler.create_block_event(node, currentTime)
#### case 2: the received block is not built on top of the last block ####
else:
depth = blockDepth + 1
#### 1- if depth of the received block > depth of the last block
if (depth > len(node.blockchain)):
#Add the block to the list of longest branches
node.longest_branch_length = blockDepth
node.longest_branches = [blockId]
if (node.last_block().miner == 16 and node.id == 0):
print("block ",
node.last_block().id, " kicked from main chain")
Node.update_local_blockchain(node, miner, depth)
#Node.update_local_blockchain_new(node,blockId)
currentTime = eventTime
if (node.type != "honest"):
#If attacker is in public mode, check if it can begin attacking
if (node.currentMode == "public"):
node.check_switch(time=currentTime)
#If attack starts, start mining private block
if (node.currentMode == "private"):
Scheduler.create_private_block_event(
node, currentTime)
#If attacker is already attacking, check if it becomes unsuccessful
else:
node.check_switch(time=currentTime)
#If attack unsuccessful, check the possibility of attacking again
if (node.currentMode == "public"):
node.check_switch(time=currentTime)
if (node.currentMode == "private"):
Scheduler.create_private_block_event(
node, currentTime)
if (node.currentMode == "public"):
Scheduler.create_block_event(node, currentTime)
#### 2- if depth of the received block = depth of the last block
elif (depth == len(node.blockchain)):
node.longest_branches.append(blockId)
#code to check main chain
if (p.ConsensusType == "FP"):
# freshest_branch = node.longest_branches[0]
# freshest_timestamp = node.network_blocks[node.longest_branches[0]].timestamp
# for branch in node.longest_branches[1:]:
# if(node.network_blocks[branch].timestamp > freshest_timestamp):
# freshest_branch = branch
# freshest_timestamp = node.network_blocks[branch].timestamp
# #update based on freshest branch
# if(lastBlockId != freshest_branch):
#If received block is fresher, update local blockchain
if (node.last_block().timestamp < blockTime):
# if(minerId == 16 and node.id == 0):
# print("block ", blockId, " accepted. timestamp: ", blockTime)
Node.update_local_blockchain(node, miner, depth)
#Node.update_local_blockchain_new(node,freshest_branch)
currentTime = eventTime
if (node.currentMode == "public"):
Scheduler.create_block_event(node, currentTime)
else:
# if(minerId == 16 and node.id == 0):
# print("block ", blockId, " not accepted in main chain FP")
uncle = Block(blockDepth, blockId, blockPrev,
blockTime, minerId, [], 0,
[]) # construct the uncle block
node.unclechain.append(uncle)
if (p.ConsensusType == "FORTIS"):
#There should be at least 2 longest branches
if (len(node.longest_branches) == 1):
print("Error")
#choose fresher branch with probability fortis_prob when there are two longest branches
if (len(node.longest_branches) == 2):
if ((blockTime <= node.last_block().timestamp) ^
(random.random() <= p.fortis_prob)):
Node.update_local_blockchain(
node, miner, depth)
#Node.update_local_blockchain_new(node,freshest_branch)
currentTime = eventTime
if (node.currentMode == "public"):
Scheduler.create_block_event(
node, currentTime)
else:
uncle = Block(blockDepth, blockId, blockPrev,
blockTime, minerId, [], 0,
[]) # construct the uncle block
node.unclechain.append(uncle)
#Choose any branch with a uniform probability if there are more than 2 longest branches
else:
branch = random.choice(node.longest_branches)
if (node.last_block().id != branch):
block = node.network_blocks[branch]
miner = p.NODES[block.miner]
#longest_branch not being updated properly
Node.update_local_blockchain(
node, miner, depth)
#Node.update_local_blockchain_new(node,random.choice(longest_branches))
#if received block is not chosen, add it to uncle chain
elif (branch != blockId):
uncle = Block(blockDepth, blockId, blockPrev,
blockTime, minerId, [], 0,
[]) # construct the uncle block
node.unclechain.append(uncle)
#If no consensus algorithm is active, add it to uncle chain
else:
uncle = Block(blockDepth, blockId, blockPrev,
blockTime, minerId, [], 0,
[]) # construct the uncle block
node.unclechain.append(uncle)
#code to update local chain
#### 3- if depth of the received block < depth of the last block, then reject the block (add it to unclechain) ####
else:
# if(minerId == 16 and node.id == 0):
# print("block ", blockId, " not accepted in main chain(not deep enough). Chain depth: ", len(node.blockchain), " block depth: ",depth)
# for i in node.blockchain:
# print ("id: ", i.id, " timestamp: ", i.timestamp, " miner: ", i.miner, "prev: ", i.previous)
uncle = Block(blockDepth, blockId, blockPrev, blockTime,
minerId, [], 0,
[]) # construct the uncle block
node.unclechain.append(uncle)
if p.hasUncles: Node.update_unclechain(node)
if p.hasTrans and p.Ttechnique == "Full":
Node.update_transactionsPool(node,
event.block) # not sure yet.
############################ Attack end Event ################################
elif (event.type == "oracle_attack_end"):
currentTime = eventTime
miner.currentMode = "public"
if (len(miner.privateblockchain) >= len(miner.blockchain)):
# print("successful attack at ", currentTime)
miner.blockchain = []
miner.blockchain = miner.privateblockchain.copy()
event.block = miner.privateblockchain[-1]
if (event.block.depth > miner.longest_branch_length):
miner.longest_branch_length = blockDepth
miner.longest_branches = [event.block.id]
elif (event.block.depth == miner.longest_branch_length):
miner.longest_branches += [event.block.id]
Scheduler.receive_private_blocks_event(event)
miner.successfulAttacks += 1
else:
# print("unsuccessful attack")
miner.unsuccessfulAttacks += 1
Scheduler.create_block_event(miner, currentTime)
# print("Switched to public mode")
miner.privateblockchain = []
