def filechain():
	blockchainGrowthPerYear = 110 * 1024 * 1024 * 1024 # bytes
	blockTime = 600 # seconds
	hashSize = 224 / 8 # bytes

	blocksPerYear =  365 * 24 * 60 * 60 / blockTime
	blockSize = blockchainGrowthPerYear / blocksPerYear

	dataSize = blockSize / 2 # size of file chunk (blockSize / 2 maximizes motivated storage capacity)

	movieSize = 8 * 1024 * 1024 * 1024 # assume the typical file is a 8GB movie
	nHashes = movieSize / dataSize

	hashPercentage = 0.5 # assume half of blockspace is occupied by money transfer transactions
	nMoviesPerBlock = hashPercentage * (blockSize - dataSize) / (hashSize * nHashes + 72 + 4 + 256) # signature, miner fee, additional info
	yearlyCapacity = nMoviesPerBlock * movieSize * blocksPerYear
	traffic = yearlyCapacity / blocksPerYear / blockTime / 1024 / 1024

	numPoolMachines = 10000 # community pool size

	totalTokenCost = 40000000 # assume that all datachain tokens are valued at 40 mio USD by the market
	rewardPercentage = 0.00000078125 / 2 # blockReward/totalTokenCost, the value is assumed to be roughly equal to bitcoin
	terabyteCostPerYear = 5 # cost of storing 1TB of data per year, in USD

	yearlyCapacityStorageCost = terabyteCostPerYear * yearlyCapacity /  1024 / 1024 / 1024 / 1024
	numMinedBlocksToBreakEven = yearlyCapacityStorageCost / (totalTokenCost * rewardPercentage)

	print "yearly capacity storage cost (USD):", yearlyCapacityStorageCost
	print "hashpower percentage to breakeven on storage (%):", 100.0 * numMinedBlocksToBreakEven / blocksPerYear
	print "movies per block:", nMoviesPerBlock
	print "storage per pool machine (GB):", yearlyCapacity / numPoolMachines / 1024 / 1024 / 1024
	print "traffic per second (MB/s):", traffic
	print "capacity per block (GB)", yearlyCapacity / blocksPerYear / 1024 / 1024 / 1024
	print "block size (MB):", float(blockSize) / 1024 / 1024
	print "yearly capacity (PB):", yearlyCapacity / 1024 / 1024 / 1024 / 1024 / 1024
	print "movies stored per year:", yearlyCapacity / movieSize

filechain()