Author Topic: [Announcement]BitShares PLAY Non-technical Whitepaper  (Read 11892 times)

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Offline klosure

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Will the "quiz game" facility allow to implement sport bets?
To avoid a massive overhead on delegates, you should rely on oracle scripts stored on the block chain that would check the results of sport events on multiple bookmaker sites, reconciliate the results to detect inconsistencies, and input the resulst in the blockchain as signed messages. The role of delegates would then be to audi the oracles code, make sure they are reliable, and run them. Codius could be a good plateform for that.

Offline pc

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The solution is as follows, the ticket result will be drawn by 2 delegates:
The first delegate's random number is only in charge of producing a number X between 1 and 3 that determines that the Xth block after him will draw the random number for the ticket. The 2th delegate could be the evil guy who is trying to attack, but he can not predict who will produce the right drawing block before 4 blocks, his attack cost is (3 * BLOCK_TICKET_SALE), but his expected return is still only 1 block_ticket_sale. The only thing game rule need is to set the draw interval 1 block before the first delegate.

I think the reasoning here is wrong. The question is what can an evil delegate gain by withholding his random secret? The answer is: he gains another chance for winning with his ticket. And using this, he can rip off the network if this second chance gives him an overall expected return that is higher than the house edge.

Suppose for example a dice-like game with 50% chance of winning and 1% house edge. I. e. if you buy a ticket for 50 shares, 50% of the time you'll lose 50 shares and 50% of the time you'll receive 99 shares in return.

The evil delegate attacker buys one ticket in every block. This costs him 5050 shares per round. In 100 of these 101 cases he cannot influence the outcome, but he will win 50 of these 100 on average, for a total return of 4950 shares. For the last ticket, he either wins normally or gets a second chance, for a winning probability of 75% and an expected return of 74.25 shares. Obviously, 4950 + 74.25 < 5050, so in this setup the evil delegate loses in the long run.
If the evil attacker owns 2 delegates or if 2 delegates collude, they cannot influence 99 of their 101 tickets. For these 99 they receive 4900.5 on average and get a second chance for the remaining two (in some cases they will even get a third chance for one of the two), i. e. 2*75%*99 shares = 148.5. 4900.5 + 148.5 < 5050, so they are still losing.

But three colluding delegates can rip off the network: they have 98 normal winning tickets yielding 4851 in returns, and 3 second chance tickets (some of the time even a third chance, and in rare cases 4 chances) for an expected return of 3*75%*99 shares = 222.75. 4851 + 222.75 = 5073.75 > 5050.
« Last Edit: December 17, 2014, 09:36:17 am by pc »
Bitcoin - Perspektive oder Risiko? ISBN 978-3-8442-6568-2 http://bitcoin.quisquis.de

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IIRC the proposed random number generation scheme had the problem that an individual delegate can decide to skip a block instead of producing a random number that would make him lose a game. (See https://bitsharestalk.org/index.php?topic=9489.msg139680#msg139680 ). Has that been addressed?

You can find infomation about this problem at
http://www.bitsuperlab.com/pdf/BitSharesPlayWhitePaper.pdf

Quote
The solution is as follows, the ticket result will be drawn by 2 delegates:
The first delegate's random number is only in charge of producing a number X between 1 and 3 that determines that the Xth block after him will draw the random number for the ticket. The 2th delegate could be the evil guy who is trying to attack, but he can not predict who will produce the right drawing block before 4 blocks, his attack cost is (3 * BLOCK_TICKET_SALE), but his expected return is still only 1 block_ticket_sale. The only thing game rule need is to set the draw interval 1 block before the first delegate.

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Offline cass

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Offline pc

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IIRC the proposed random number generation scheme had the problem that an individual delegate can decide to skip a block instead of producing a random number that would make him lose a game. (See https://bitsharestalk.org/index.php?topic=9489.msg139680#msg139680 ). Has that been addressed?
Bitcoin - Perspektive oder Risiko? ISBN 978-3-8442-6568-2 http://bitcoin.quisquis.de

Offline xeroc

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yet another forum :( ... puh ..

anyway .. +5% for the nontech WP .. good luck with the DAC!

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BitShares PLAY Non-technical Whitepaper

Please visit playtalk.org for more details

1.0 Introduction

Bitshares PLAY(PLAY in short)Leverages the block chain technology, attempts to establish a decentralized autonomous game platform. Any third party can develop various provably fair games, including types that are never seen before. These games feature entertainment and fairness at the same time. Meanwhile, PLAY embodies the function of random number generation (see appendix for technical details) and custom asset and exchange are accessible to third-party developers, providing fairness and asset issuing with convenience and technical support.

2.0 Functionality

2.1 Type of games supported by PLAY
On-chain games refer to games that run its entire logic on the block chain and that are independent from any external centralized institutions (no risk of trust)
 
2.1.1games on probability
Typically, Dice, Chance Coin and etc.

2.1.2 Quiz games
The guesswork of whether something will happen or how something will happen in the future.
For example, whether celebrities will get married or divorce in a specific amount of time
Data needs to be put into the blockchain after events happen off-line. On Bitshares Play, which leverages DPOS, the job can be done by delegates. Because delegates are elected by PLAYshares holders, we believe the results of vote are reliable. (If the result is obviously false according to facts, the consequence is shared by the PLAY shares holders who elected the delegates, which means it will fall on the whole community, in which sense, it is still fair.) 

2.1.3Multiple-person vote-based SPG
This is a brand new interactive multiple-unit game proposed by ByteMaster.
An example can best illustrate the mechanism. Chess would be different from its traditional form whereby only two people are involved, while on the PLAY platform there would be two groups of users. Every ID has its color field,making it a game between the black and the white game. How a round should be played will be determined by the group’s vote and the weight of each ID’s vote depending on the balance in the account of the ID.
This is an unprecedented type of game, even for the cryptocurrency field.

2.1.4 Chess Games
This type of game includes simple chess game and possibly board games and pokers.

2.1.5 Probability and Strategy Combined
This type is a combination of 2.1.1 and 2.1.4 which require both luck and planning, like Cannot Stop and Bingo.   

2.2 The definition of Decentralized Game Asset and P2P exchange

Traditional games have the concept of game assets and equipment. PLAY allows users to issue custom assets, which means game developers are allowed to issue their own customized assets (either game tokens or gear objects), and realize deposit and withdrawal inside the games or control the total amount of assets by reading the asset ledger on the blockchain. At the same time, the tokens and gear objects are exchangeable on the platform of PLAY. Players can freely purchase or sell these assets, through which, inter-server and inter-game p2p economic systems are established, replacing traditional asset issue models.。

If on-chain games as described in 2.1 gains enormous user base, PLAY is expected to welcome more game developers to issue their assets for users’ attention. By then, custom assets’ qualification bidding could also be introduced as one of the possible profit models when huge user base offers possibilities for many other revenue channels.

PLAY encourages exchange and market to be built in traditional games to realize decentralized game asset exchange without the necessary process to get familiar for the third-party platforms.


3.0 Introduction of PLAY’s built-in Random Number Generation (RNG)
Random numbers are used in many scenarios when their generations have been a problem for very long. A general principle is, the generation of random numbers is better to be done without any control of a particular individual. Therefore, to make a future block the source of random number is still unreliable, because the randomness is still in the end decided by a certain individual and it is impossible to prove whether the regarding individual is honest.
 
PLAY adopts a distributed algorithm for random number generation , leveraging delegates in the DPOS structure to provide the randomness. PLAY delegates generate private key data and publish the hash of the key data when a block is published.

In the end the random number employed is generated by a successive multiple (at least 101 or more) number of key data, so that as long as one delegate is honest and hasn’t leaked his data,。we can safely assume that no one could know the random number generated in the end, making the number fair and reliable.

Appendix:

Development Roadmap
A basic asset transaction, ID, CP accounts and built-in exchange and models of exchange and trading.
B on-chain game platform (including 1 or 2 on-chain game demonstration), custom assets issue, deposit and withdrawal, API reading
C light wallet
D Quiz game,, third-party game developer integration
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