[ANN][CHA] Chancecoin, SuperNET core coin for betting in a decentralized casino - page 86.

phm

full member

Activity: 378

Merit: 110

DATABLOCKCHAIN.IO SALE IS LIVE | MVP @ DBC.IO

Quote from: magician on March 28, 2014, 08:13:53 PM

Quote from: phm on March 28, 2014, 06:57:42 PM

Quote from: magician on March 27, 2014, 09:51:07 PM

Having heard the community's concerns about block hashes being prone to manipulation, we have decided not to use block hashes to resolve bets. Rather, we will be using New York Lottery Quick Draw numbers to resolve bets.

New York Lottery Quick Draw

Quick Draw numbers are drawn every four minutes, every day of the week. The numbers are published online shortly after they are drawn. The drawing selects 20 numbers randomly from a pool of numbers 1 through 80, without replacement. In the newest version of the Chancecoin protocol, a bet seen in the blockchain will be resolved with the next available set of Quick Draw numbers. We use combinadics to convert these numbers to a random uniform variable, and use it to resolve the bet.

We have more updates coming this weekend.

I think that with this solution miners will still be able to manipulate the results with the following algorithm:

1. make a bet
2. mine a block
3. if current set of Quick Draw numbers makes me a winner then publish block
4. wait for the next set of Quick Draw numbers
5. goto 2

Of course someone else may mine the block in the meantime, but a large pool with 30-40% hashrate of the network will make the results considerably unfair. Pool with 90% hashrate will be able to win almost every time. How will you prevent that?

The bet is resolved based on the first set of NY Lottery Quick Draw numbers that are published strictly after the block is mined, so it is not possible to game the system by waiting for favorable lottery numbers. Thanks for the question! This is an important clarification I should have made earlier.

Not sure if you know this, but timestamps in blockchain are prone to limited manipulation, rules of validating them are quite fuzzy. "A timestamp is accepted as valid if it is greater than the median timestamp of previous 11 blocks, and less than the network-adjusted time + 2 hours". So in fact nothing prevents miner from sending the block with timestamp few minutes in the past or in the future, timestamps in consecutive blocks don't have to always increase. How will you enforce such rule if you don't really know the real time when given block was mined?

nergpchen

member

Activity: 78

Merit: 10

Like XCP

520Bit

sr. member

Activity: 602

Merit: 252

Quote from: englishbad on March 29, 2014, 01:26:52 AM

can you add me？ok，thank you！

What are you doing here?

bingjiw

newbie

Activity: 37

Merit: 0

Some questions:

1. It is better that if the gambler can bet directly by using BTC. An automatic exchange from BTC to Chancecoin can be applied if necessary. Is this possible?

2. How to convert Chancecoin back to BTC? Will you build a Decentralized Exchange website like https://testnet.counterwallet.co ?

3. If a holder of Chancecoin will become a part of the house automatically, then what happens when a guy use his Chancecoin to bet? gamble against himself?

thanks

englishbad

sr. member

Activity: 364

Merit: 250

can you add me？ok，thank you！

520Bit

sr. member

Activity: 602

Merit: 252

Error happened while running chancecoind.py server. Block 292092 could not pass, why?

Code:

c:\chancecoin>chancecoind.py server
Config file: C:\Users\xxxxxx\AppData\Roaming\Chancecoin\chancecoin\chancecoin.conf; Exists: Yes
Status: RESTART
Block: 292092
Bet: 1BckY64TE6VrjVcGMizYBE7gt22axnq6CM bet 0.001 CHA with chance 50.0 and payout 1.96 [valid]
Traceback (most recent call last):
  File "C:\chancecoin\chancecoind.py", line 478, in 
    blocks.follow(db)
  File "C:\chancecoin\lib\blocks.py", line 572, in follow
    parse_block(db, block_index, block_time)
  File "C:\chancecoin\lib\blocks.py", line 71, in parse_block
    parse_tx(db, tx)
  File "C:\chancecoin\lib\blocks.py", line 50, in parse_tx
    bet.resolve(db)
  File "C:\chancecoin\lib\bet.py", line 129, in resolve
    block_time_ny = block_time.astimezone(ny_zone)
TypeError: astimezone() argument 1 must be datetime.tzinfo, not None

520Bit

sr. member

Activity: 602

Merit: 252

Quote from: Venetian on March 29, 2014, 12:49:24 AM

Quote from: 520Bit on March 28, 2014, 11:43:59 PM

Any details in how to install from the source?

Code:

c:\chancecoin>chancecoind.py
Traceback (most recent call last):
  File "C:\chancecoin\chancecoind.py", line 30, in 
    from lib import (config, util, exceptions, bitcoin, blocks)
  File "C:\chancecoin\lib\blocks.py", line 16, in 
    from . import (send, order, btcpay, bet, burn, cancel)
  File "C:\chancecoin\lib\bet.py", line 11, in 
    import urllib3
ImportError: No module named urllib3

c:\chancecoin>gui.py
Traceback (most recent call last):
  File "C:\chancecoin\gui.py", line 3, in 
    from PyQt4.QtCore import *
ImportError: No module named PyQt4.QtCore

c:\chancecoin>

We recommend using Python version 3.2.5 when you are compiling from source. You can get it at https://www.python.org/download/releases/3.2.5.

It looks like you are missing a few packages. If you are using pip on powershell, run "pip install urllib3" to install urllib3. Otherwise, you can get the urllib3 package from this page: https://pypi.python.org/pypi/urllib3

You can get the PyQt package from this page: http://www.riverbankcomputing.com/software/pyqt/download

Thanks for your patience. We'll get the windows binary out in the next few days!

Thanks for your reply. Does it have 1 BTC limited to burn like Counterparty did?

escrowman

sr. member

Activity: 262

Merit: 250

chancecoin seems no change any more

Venetian

newbie

Activity: 50

Merit: 0

Quote from: 520Bit on March 28, 2014, 11:43:59 PM

Any details in how to install from the source?

Code:

c:\chancecoin>chancecoind.py
Traceback (most recent call last):
  File "C:\chancecoin\chancecoind.py", line 30, in 
    from lib import (config, util, exceptions, bitcoin, blocks)
  File "C:\chancecoin\lib\blocks.py", line 16, in 
    from . import (send, order, btcpay, bet, burn, cancel)
  File "C:\chancecoin\lib\bet.py", line 11, in 
    import urllib3
ImportError: No module named urllib3

c:\chancecoin>gui.py
Traceback (most recent call last):
  File "C:\chancecoin\gui.py", line 3, in 
    from PyQt4.QtCore import *
ImportError: No module named PyQt4.QtCore

c:\chancecoin>

We recommend using Python version 3.2.5 when you are compiling from source. You can get it at https://www.python.org/download/releases/3.2.5.

It looks like you are missing a few packages. If you are using pip on powershell, run "pip install urllib3" to install urllib3. Otherwise, you can get the urllib3 package from this page: https://pypi.python.org/pypi/urllib3

You can get the PyQt package from this page: http://www.riverbankcomputing.com/software/pyqt/download

Thanks for your patience. We'll get the windows binary out in the next few days!

520Bit

sr. member

Activity: 602

Merit: 252

Any details in how to install from the source?

Code:

c:\chancecoin>chancecoind.py
Traceback (most recent call last):
  File "C:\chancecoin\chancecoind.py", line 30, in 
    from lib import (config, util, exceptions, bitcoin, blocks)
  File "C:\chancecoin\lib\blocks.py", line 16, in 
    from . import (send, order, btcpay, bet, burn, cancel)
  File "C:\chancecoin\lib\bet.py", line 11, in 
    import urllib3
ImportError: No module named urllib3

c:\chancecoin>gui.py
Traceback (most recent call last):
  File "C:\chancecoin\gui.py", line 3, in 
    from PyQt4.QtCore import *
ImportError: No module named PyQt4.QtCore

c:\chancecoin>

overthetop2011

hero member

Activity: 678

Merit: 500

I am interested in this project.

Wondering more details about the dev group...

allwelder

legendary

Activity: 1512

Merit: 1004

interesting project.

magician

member

Activity: 113

Merit: 10

Chancecoin developer

Quote from: Cryptokk on March 28, 2014, 08:19:28 PM

Sad "CHA" is already taken Wink

There is only one true CHA, and it's Chancecoin.

magician

member

Activity: 113

Merit: 10

Chancecoin developer

Quote from: JahPowerBit on March 28, 2014, 08:11:48 PM

Quote from: magician on March 27, 2014, 09:51:07 PM

Having heard the community's concerns about block hashes being prone to manipulation, we have decided not to use block hashes to resolve bets. Rather, we will be using New York Lottery Quick Draw numbers to resolve bets.

New York Lottery Quick Draw

Quick Draw numbers are drawn every four minutes, every day of the week. The numbers are published online shortly after they are drawn. The drawing selects 20 numbers randomly from a pool of numbers 1 through 80, without replacement. In the newest version of the Chancecoin protocol, a bet seen in the blockchain will be resolved with the next available set of Quick Draw numbers. We use combinadics to convert these numbers to a random uniform variable, and use it to resolve the bet.

We have more updates coming this weekend.

If you can find a solution, it's much more elegant to use only the blockchain without external source.

If you use multiple blocks to generate a random number, it will already be more difficult to cheat.

For example :
- Use a block B1 to generate a number N1 between 1 and 100
- Use the block (B1-N1) to generate a number N2 between 1 and 100
- Use the block (B1-N1-N2) to generate a number N3 between 1 and 100
- ... repeat ...
- Use N100 as pseudo-random number.

This is just an example that requires more thought, but I think it is possible to make cheating difficult enough, for it is not profitable.

I like the idea of having a random number generator in Counterparty. Potentially, this allows to play Poker, Blackjack, etc... And it would be a natural evolution of bets that already exist in Counterparty.
IMHO it is less cleaner to implement a new coin just for this functionality. The same question arises for the hundreds of LTC clones. Intuitively I think it is not good for LTC. But I think no one ever will know the real answer..

We considered a solution similar to this. The problem is that a devious gambler can always aggressively mine the last block that is to be used as a source of randomness to settle a particular bet, even if various other blocks are used in the randomness calculation. Hence we transitioned to the external source solution.

Cryptokk

newbie

Activity: 56

Merit: 0

Sad "CHA" is already taken Wink

magician

member

Activity: 113

Merit: 10

Chancecoin developer

Quote from: phm on March 28, 2014, 06:57:42 PM

Quote from: magician on March 27, 2014, 09:51:07 PM

Having heard the community's concerns about block hashes being prone to manipulation, we have decided not to use block hashes to resolve bets. Rather, we will be using New York Lottery Quick Draw numbers to resolve bets.

New York Lottery Quick Draw

Quick Draw numbers are drawn every four minutes, every day of the week. The numbers are published online shortly after they are drawn. The drawing selects 20 numbers randomly from a pool of numbers 1 through 80, without replacement. In the newest version of the Chancecoin protocol, a bet seen in the blockchain will be resolved with the next available set of Quick Draw numbers. We use combinadics to convert these numbers to a random uniform variable, and use it to resolve the bet.

We have more updates coming this weekend.

I think that with this solution miners will still be able to manipulate the results with the following algorithm:

1. make a bet
2. mine a block
3. if current set of Quick Draw numbers makes me a winner then publish block
4. wait for the next set of Quick Draw numbers
5. goto 2

Of course someone else may mine the block in the meantime, but a large pool with 30-40% hashrate of the network will make the results considerably unfair. Pool with 90% hashrate will be able to win almost every time. How will you prevent that?

The bet is resolved based on the first set of NY Lottery Quick Draw numbers that are published strictly after the block is mined, so it is not possible to game the system by waiting for favorable lottery numbers. Thanks for the question! This is an important clarification I should have made earlier.

JahPowerBit

sr. member

Activity: 335

Merit: 255

Counterparty Developer

Quote from: magician on March 27, 2014, 09:51:07 PM

Having heard the community's concerns about block hashes being prone to manipulation, we have decided not to use block hashes to resolve bets. Rather, we will be using New York Lottery Quick Draw numbers to resolve bets.

New York Lottery Quick Draw

Quick Draw numbers are drawn every four minutes, every day of the week. The numbers are published online shortly after they are drawn. The drawing selects 20 numbers randomly from a pool of numbers 1 through 80, without replacement. In the newest version of the Chancecoin protocol, a bet seen in the blockchain will be resolved with the next available set of Quick Draw numbers. We use combinadics to convert these numbers to a random uniform variable, and use it to resolve the bet.

We have more updates coming this weekend.

If you can find a solution, it's much more elegant to use only the blockchain without external source.

If you use multiple blocks to generate a random number, it will already be more difficult to cheat.

For example :
- Use a block B1 to generate a number N1 between 1 and 100
- Use the block (B1-N1) to generate a number N2 between 1 and 100
- Use the block (B1-N1-N2) to generate a number N3 between 1 and 100
- ... repeat ...
- Use N100 as pseudo-random number.

This is just an example that requires more thought, but I think it is possible to make cheating difficult enough, for it is not profitable.

I like the idea of having a random number generator in Counterparty. Potentially, this allows to play Poker, Blackjack, etc... And it would be a natural evolution of bets that already exist in Counterparty.
IMHO it is less cleaner to implement a new coin just for this functionality. The same question arises for the hundreds of LTC clones. Intuitively I think it is not good for LTC. But I think no one ever will know the real answer..

phm

full member

Activity: 378

Merit: 110

DATABLOCKCHAIN.IO SALE IS LIVE | MVP @ DBC.IO

Quote from: magician on March 27, 2014, 09:51:07 PM

Having heard the community's concerns about block hashes being prone to manipulation, we have decided not to use block hashes to resolve bets. Rather, we will be using New York Lottery Quick Draw numbers to resolve bets.

New York Lottery Quick Draw

Quick Draw numbers are drawn every four minutes, every day of the week. The numbers are published online shortly after they are drawn. The drawing selects 20 numbers randomly from a pool of numbers 1 through 80, without replacement. In the newest version of the Chancecoin protocol, a bet seen in the blockchain will be resolved with the next available set of Quick Draw numbers. We use combinadics to convert these numbers to a random uniform variable, and use it to resolve the bet.

We have more updates coming this weekend.

I think that with this solution miners will still be able to manipulate the results with the following algorithm:

1. make a bet
2. mine a block
3. if current set of Quick Draw numbers makes me a winner then publish block
4. wait for the next set of Quick Draw numbers
5. goto 2

Of course someone else may mine the block in the meantime, but a large pool with 30-40% hashrate of the network will make the results considerably unfair. Pool with 90% hashrate will be able to win almost every time. How will you prevent that?

magician

member

Activity: 113

Merit: 10

Chancecoin developer

The burn address is still the same, and you still need to burn to invest in the house. The house edge is still 2%. We will give a detailed explanation this weekend about how betting is settled for those who are interested in the technical details.

bingjiw

newbie

Activity: 37

Merit: 0

Is the burn address (1ChancecoinXXXXXXXXXXXXXXXXXZELUFD) still available ?

Do we still need to burn to invest as house ?

What about the house edge if we change to use the new york lottery ?

Topic: [ANN][CHA] Chancecoin, SuperNET core coin for betting in a decentralized casino - page 86. (Read 146141 times)