Take a chance to win SBI! Provably fair and random through upvoting. 11 SBI pot.

lucky-elephant in Hive SBI • 2 months ago

Several months ago I entered a contest to win SBI from @noloafing. In the interest of paying it forward I am running a contest also. With enough SBI you can receive a “basic income” in the form of upvotes from SBI accounts. I hope it gives you a start.

All eligible upvoters will have a chance to win. Upvoters will be eligible with at least a .001 Hive upvote after the seven days have passed.

The winners will be determined by the txid of their upvote. Highest to lowest.

1st - 5 SBI
2nd - 3 SBI
3rd - 2 SBI
4th - 1 SBI

SBI will be awarded after the 7 days.

#sbi #contest #lottery #leofinance #palnet #reward-app #hive-sbi #gems

2 months ago in Hive SBI by lucky-elephant

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hykss 2 months ago

Upvoted !
Oh wait ... is txid incremental ? :D
Thank you for organising the giveaway

Posted Using LeoFinance ^Beta

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3 votes

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noloafing 2 months ago

This is an awesome idea.

I'm glad I was able to spur more competitions!

Cheers,
NL

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2 votes

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crokkon 2 months ago

Hi @lucky-elephant,
I'm not here for the SBI, I just want to let you know that the txid is not suitable as a 'random' variable for giveaways/contests/...

As you can see here, I've created a vote operation on your post starting with 0xfff:

While the txid itself is 'random', it is known before the transaction is sent to the blockchain. By modifying the parameters, I can try out several variations of the vote operation (and the resulting txid) before sending the transaction to the chain.

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1 vote

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lucky-elephant 2 months ago

Well, thanks for the post! My understanding was the txid could not be manipulated. How is it possible? What is the procedure? Is there a way to fix it?

I believe the game I run (Hi-Lo) is okay because players do not know which they are to match until the end. Any advice you can give would be appreciated.

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crokkon 2 months ago

Here's the raw transaction for my vote:

{
'expiration': '2020-12-28T15:26:39', 
'ref_block_num': 8921, 
'ref_block_prefix': 3788342440, 
'operations': [
  ['vote', {
    'voter': 'crokkon', 
    'author': 'lucky-elephant', 
    'permlink': 'take-a-chance-to-win-sbi-provably-fair-and-random-through-upvoting-11-sbi-pot', 
    'weight': 8540}]
  ],
 'extensions': [], 
'signatures': ['20345a9...']}

all fields except signatures are chosen by the user before signing the transaction. If I vary expiration, ref_block_num, ref_block_prefix (with limitations, values depend on previous blocks and varie over time) or weight (what I did here), I'll get a different signature and therefore a different transaction ID. This all happens offline. Once I'm 'happy' with the txid (e.g. sufficiently high number), I can send the signed transaction to the blockchain. This is obviously nothing you could do easily by clicking the upvote button on peakd/leofinance/hive.blog/..., but with a bit of scripting this is no problem.

EpicDice also had to learn this the hard way :D

I think your Hi-Lo game cannot be gamed by your participants, but you could take influence on the outcome by posting your comment with a transaction id for one or the other result.

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tomesd 2 months ago

This is interesting!

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