Introducing PevPot.com The Bitcoin Lottery

[TwitchySeal]

Seems like a cool idea - Sent 0.025, then went to register/sign my address and got the "coming soon" message.  Will this be ready for the draw?

Here's the transaction though (my address as also tagged on blockchain.info)

https://blockchain.info/tx/6d76aa4d3684fd392d71f271b44f7fce26368933368b5a86c979c434a91eb7e6


 Address: 1JqxhKj4CdRqFb7mGdXVMYTMy1MQ5qShsn

(also, initially I accidentally sent 0.000025 BTC because my wallet was set to mbtc and I wasn't thinking, that one is still without verification - even though the fee was more than double the send amount haha.  I sent 0.025 BTC a few minutes after)

Thanks for sharing this over at betcoin dooglus

[katerniko1]

i need to say that this sounds interesting just from reading +EV lottery you got my attention at that
so i will try it for sure.
regards.
-Katerniko1

[Coef]

Very interesting idea. So basically the more the players gambled, the less positive the EV becomes.
I will surely join it when the provably fair system is finalized.

The Bitcoin Lottery
draw #1 ends in 869 bitcoin blocks (#1233000)

I see on the above on the page, but what does that #1233000 stand for?

[Coef]

I see on the above on the page, but what does that #1233000 stand for?

Bitcoin block number 1233000



(BTW, I really appreciate all these questions as they help me understand what's not clear about the site to improve it. I got a lot of work cut out for me )

Not sure if I am understanding you correctly there, but the current bitcoin block height is 383134, shouldn't the draw 1 end in block 384000?
BTW, it will take roughly 16 years to get to block 1233000. I am not sure I want to keep my bet stuck for that long lol.

[Coef]

As thanks for pointing that out, I'll give you 0.1 BTC in tickets. What address would you like it to go to, if you win it?  

Oh thanks. 1DnAp7MfiGEkT7MknroXfpgDwP4bM1XwCC please.

[RHavar]

Oh thanks. 1DnAp7MfiGEkT7MknroXfpgDwP4bM1XwCC please.

https://www.pevpot.com/registrations/7182f4d2-f26f-4400-976c-7b546977763a

If the 0.1 wins (tx aa02a98b2dada8c3e3f5cf1ccc7a2f0ea1cc2cfaecc4e3be4f8df51a92505cb8) you'll get your prize automatically sent to you without further action required. Good luck!

[Coef]

Oh thanks. 1DnAp7MfiGEkT7MknroXfpgDwP4bM1XwCC please.

https://www.pevpot.com/registrations/7182f4d2-f26f-4400-976c-7b546977763a

If the 0.1 wins (tx aa02a98b2dada8c3e3f5cf1ccc7a2f0ea1cc2cfaecc4e3be4f8df51a92505cb8) you'll get your prize automatically sent to you without further action required. Good luck!

Nice.



I notice a small issue while I check the link. When I view it using Firefox, the text goes beyond the gray box and I am unable to read the complete message.
Screenshot using Firefox:



When I view it using Chrome, the word wrapping works perfectly.
Screenshot using Chrome:

[dooglus]

Criticism encouraged, ...

"Provably fair betting means that we give you a hash of the bet outcome before you make the bet to prove that we did not cheat."

That's presumably copy/pasted from one of your other sites. It doesn't apply to this game.

Frequently Asked Questions

What is my chance of winning

Needs a question mark at the end. Same for other questions - a few are missing question marks. And "How many confirmations needed" is missing an "are".

"The draw actually ends in the xxxxx000 block" - I'd use 3 x's, since block numbers are 6 digits at the moment, and will be for years to come.

"There's quite a few reasons for this" - there is reasons?

[dooglus]

PROVABLY FAIR DETAILS
...because you shouldn't have to take our word for it

The pot starts with 90% of the money that sponsors sent during the previous draw (10% is kept for running the site).

It occurred to me (since this is the first thing listed on the provably fair page) that we can't be sure you're not keeping more than 10% of the sponsor money.

I see "Thanks to our sponsors for putting 0.17658 btc in this draw's pot!", but I can't tell how much each one paid you for you to arrive at that total. I expect I could go through the sponsorship pages one at a time (https://www.pevpot.com/sponsors/1, https://www.pevpot.com/sponsors/2, etc.) to check it but that's kind of a pain, especially as the total number of sponsorship pages grows.

Every satoshi sent to the lottery address during the draw blocks are given 1 chance of winning

Two things: it's not *every* satoshi. It's only the ones making up big-enough payments. There's a dust threshold.

And every one *is* given, not *are* given.

Point 5 is missing a trailing period.

Point 7: some people might not be happy signing a message saying something as ambiguous as "pevpot". It's best practice to be explicit about what a signed message is for. For example I might like to state that the signature is for the sole purpose of claiming a pevpot.com win, and is not to be considered as proof of ownership for any other purpose. Or words to that effect. Maybe you can allow the "purpose" field to be free text so long as the first 6 characters are "pevpot". Or maybe I'm just running out of nits to pick.

[Altcoin4life]

Sent some bits to try it and see if I have any luck left

[dooglus]

Thanks Dooglus, I've sent 0.1 BTC to your sponsor ad in appreciate for the help.

Sweet, thanks.

I think that's going to be out of scope for the provably fair (or maybe I'll add to the FAQ) but if you want to verify you can add this:

Code:

xpub6EAA7AfEvViuBs6sCp81j73ParX6MXTgiXNaLNbKe3PM9NtrYiP8YBbkPQLwWRZzQFBCDRn1abVymEF3VWZW28d2eciT962FHDwUAgjPN4Y

to a bip32 wallet, and the sponsor contribution will be 90% of the amount received during the previous round.

I think that's a fine FAQ answer, maybe linked to from the PF page.

[dooglus]

In 6 blocks (when the height ends in xxx006) we get its block hash (in hex) and apply the key-stretching

This is a little ambiguous. Do you include the "0x" prefix? Do you use uppercase or lowercase hex? Do you include leading zeroes?

I propose you specify that you will use the 64 lowercase characters given by getblockhash, for example:

$ bitcoin-cli getblockhash 383006
00000000000000000ef86b27c174df6a412c0ce43eab1d532034555749294137

Here's an example with a smaller iteration count using that block hash, to check we arrive at the same result:

> Buffer(forge.pbkdf2('00000000000000000ef86b27c174df6a412c0ce43eab1d532034555749294137', 'pevpot', 100000, 32, 'sha256'), 'binary').toString('hex')
'39aed3d2eff372916100106e355384495d1794320d4c3cb4c2e0e48cc36bbd06'

Or in Python:

$ python
Python 2.7.9 (default, Mar  1 2015, 12:57:24)
[GCC 4.9.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import hashlib, hmac, pbkdf2
>>> pbkdf2.PBKDF2('00000000000000000ef86b27c174df6a412c0ce43eab1d532034555749294137', 'pevpot', 100000, hashlib.sha256, hmac).hexread(32)
'39aed3d2eff372916100106e355384495d1794320d4c3cb4c2e0e48cc36bbd06'

[RHavar]

In 6 blocks (when the height ends in xxx006) we get its block hash (in hex) and apply the key-stretching

This is a little ambiguous. Do you include the "0x" prefix? Do you use uppercase or lowercase hex? Do you include leading zeroes?

I propose you specify that you will use the 64 lowercase characters given by getblockhash, for example:

$ bitcoin-cli getblockhash 383006
00000000000000000ef86b27c174df6a412c0ce43eab1d532034555749294137

Here's an example with a smaller iteration count using that block hash, to check we arrive at the same result:

> Buffer(forge.pbkdf2('00000000000000000ef86b27c174df6a412c0ce43eab1d532034555749294137', 'pevpot', 100000, 32, 'sha256'), 'binary').toString('hex')
'39aed3d2eff372916100106e355384495d1794320d4c3cb4c2e0e48cc36bbd06'

Or in Python:

$ python
Python 2.7.9 (default, Mar  1 2015, 12:57:24)
[GCC 4.9.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import hashlib, hmac, pbkdf2
>>> pbkdf2.PBKDF2('00000000000000000ef86b27c174df6a412c0ce43eab1d532034555749294137', 'pevpot', 100000, hashlib.sha256, hmac).hexread(32)
'39aed3d2eff372916100106e355384495d1794320d4c3cb4c2e0e48cc36bbd06'

Confirming that is the case, and that for block 383006 I also arrive at at 39aed (with the smaller iteration count). I'll add this to the provably fair as an example.

I'm working on publishing a draw verification script, which you can run in the browser, which gets its data from blockcypher (a completely independent source) to be able to verify the outcomes. This will help me crosscheck my results, and make it easy for people to verify themselves.

[RHavar]

Just 27 blocks to go!

The pot is currently a rather incredible +EV 2.55%!


I've updated the FAQs, and provided some concrete examples to the provably fair to remove ambiguity. Unfortunately for technical reasons, this draw will not automatically finalize itself, and I'll need to do it tomorrow morning.


Good luck all!


Also if you want to sponsor a site (or help one of the existing ones, now's your chance! https://www.pevpot.com/sponsors )

[NLNico]

Lol, 6 coin + 11 coin "last moment" bets Still 8 blocks ~80 mins, but cool to see the prize grow..... almost BTC24 prize for winner now!


Still +0.74% = same as investors take on most crowd-funded dice sites (aka "investors" should also bet on PevPot )

[ndnh]

And the block is mined!

draw #1 ends in 0 bitcoin blocks (#384000)
Current Pot: 23.88 BTC

Let us see who is gonna win

[NLNico]

Nice.. gotta wait till block #384006 now.. then from that block hash we can calculate the result hash (calculation also takes some time.)



So if we calculated the result hash, can we just do: parseInt('hash',16)%tickets) or do we need some big int special since it's a 256 bit number ? I don't know much about that

edit: https://www.blocktrail.com/BTC/block/000000000000000009b7fb236187f120a0c86eb8785f099a8d197dd34b9d2553 so calculating result hash (called stretched block hash by PevPot), might take 1-2 hours from now.

[Mitchell]

Please let me win those 24BTC. I'll make sure they get used properly.

[dooglus]

edit: https://www.blocktrail.com/BTC/block/000000000000000009b7fb236187f120a0c86eb8785f099a8d197dd34b9d2553 so calculating result hash (called stretched block hash by PevPot), might take 1-2 hours from now.

You can calculate it that fast?

I timed 5,000,000 iterations and found it took 93 seconds.

So 5 billion iterations would take me 1000 times longer, or 25.8 hours.

I guess it's possible there's a faster way of doing it.

Here's my attempt at producing the sorted list of qualifying bets:

008922cf634846778343074c6994c9e39584bf1a891c14cdcb2d1b89c7244a99  0.00400000 :          0 -     399999
0b8d8888ad813aaa2135b4483e0f08fa2e51b425e093edb65502313d3e238970  0.01237280 :     400000 -    1637279
105f88313a78eaee08b00cd8aac14dd1a5679323174166a2e3bf4a089779a016  0.01494000 :    1637280 -    3131279
108272f527838860d2a69fd35f3f0aeffdd2fa3cf371f1cba4218a76968991ed  0.20000000 :    3131280 -   23131279 <-- me
1efba412cbd39315079eecac684cbebe4cad5dc6060fae67ca6448c9b357996d  4.99997120 :   23131280 -  523128399
257b6b842d50af5ba7622655a9e01f33fdbe797b3386ff7284de9a5dd3be5e25  0.00097120 :  523128400 -  523225519
2842d8640b3a0cc5b2a587449a6920305a62bfff7f72b1d02a07fefb20a9ab64  0.00097135 :  523225520 -  523322654
3044f6f79a05ba0a946543a943d8052baef0e3f8b6f079d727ac8ebc3c223668  0.09990000 :  523322655 -  533312654
33e38d95c430df1174135a0105b1ca8e0722bbf891966b1bbc7d3e072cd15e1e  0.00128000 :  533312655 -  533440654
35a837ae03e7c4da8af2e4b84ed1ffcc86ce3444b683dfd5c62167521aa6c350  0.00282422 :  533440655 -  533723076
3bdf09d87f85beab37105858c608346e3c0a8743fc9bc49019c7d5bc5e8c47a4 10.82969911 :  533723077 - 1616692987
4544f527dc04e5b6321beabd7e182a898c1e0342fd6a37381b59f63d507869e2  0.00100000 : 1616692988 - 1616792987
46718ce9f295d6ab58823245c049a252fde1167327ecc932b231d9d2291fd0ab  0.00020000 : 1616792988 - 1616812987
46ef2aec2aad64364e40581d8e1de01ab4eecf9396e00218070980c594587e4f  0.02497120 : 1616812988 - 1619310107
47b32e99b12c0d28f4794d686a97e0e75a3090669fde6218a11fa60900e1713a  0.00200000 : 1619310108 - 1619510107
4cd1f8d05f8727761204843b3de9e37959da7ead8ef9d3b955555aace30f3915  0.00297135 : 1619510108 - 1619807242
529d66622b0fd4c2e5d9c66b158fc789abf66bb55f2e17867401244f244825b4  5.92947120 : 1619807243 - 2212754362
56fb6cf4c16d443ec11a81e14684509e16d8ff0fd01cb08e5332d00b9090182a  0.04997135 : 2212754363 - 2217751497
577cdd0adee0e85da3c17f054bc9f02aa126c37267904b9907d4427a2c2fd22e  0.99990000 : 2217751498 - 2317741497
59d7e4447f805793b0a776e0f5e14fcd0761af067ae7cc89ff7f327d3c22236f  0.00487135 : 2317741498 - 2318228632
6658e43f7f65cef2578aa98bb09db14c06ecb86d31c77b216238cab3b5876521  0.00010000 : 2318228633 - 2318238632
67b5fc0c3086f1c0c0436c3e9d9cc0ab1591b4a2624f634336b94c050ecf4aca  0.00809920 : 2318238633 - 2319048552
69a67d0f266927a7dbb6b64c46d89c72d5c80c707a07134ded751a9ffff314ee  0.00067120 : 2319048553 - 2319115672
6b77502e40baf085bab0b9999085f165360a27f6b92c9162a5124976ea1f36ec  0.00010000 : 2319115673 - 2319125672
6d76aa4d3684fd392d71f271b44f7fce26368933368b5a86c979c434a91eb7e6  0.02500000 : 2319125673 - 2321625672
6e1eaac7b74cd74bb916fc17a9817271ddf09e0ef48f7b79e3179591a712949f  0.00097135 : 2321625673 - 2321722807
74ccf8ca8bd0ef8061601ce76c6d1af6169cef926c541ea38c58dbcc9d9ce75a  0.00060000 : 2321722808 - 2321782807
7506e19fc92c0feac90164c46cdfd3e7b7b1e6366a53bcd4c777fc7fa46060d9  0.00997035 : 2321782808 - 2322779842
80d0dc5d3e976a79a8902eccaf5b1c74322a5759b2c1e81d5d27fc436dbe2e3d  0.00287135 : 2322779843 - 2323066977
85cec4d3a20c582145c88f46210ddd8cdf82879ea7bc02cb779a9381a9f82028  0.00097120 : 2323066978 - 2323164097
91730b6ece70de9dde9d09da66d2f23f112b0494f0efb0b837483eb0f8821049  0.00120535 : 2323164098 - 2323284632
96421ff7299afde33df2bd968580d7576579adc3392948743a9c2ba0816aae24  0.00050000 : 2323284633 - 2323334632
9bd9d3e96f007dc5ec53ebd32219afd0e49e0e4c514824fe0b65b5c58d705e4b  0.00097120 : 2323334633 - 2323431752
9fd4add5da8ff544a0b833b3348a276e5f4cb6d49b3137bb5ab090b740829b14  0.00040000 : 2323431753 - 2323471752
a1f8dddf6d5863c18fdb79680769e60f3ea085f84c4268782e528335c12dae2c  0.00040000 : 2323471753 - 2323511752
a497201c7fa64a5c0b8fd09657f9d2188b31d07e4fecebac9364abaf1ba2c967  0.00010000 : 2323511753 - 2323521752
a5d197065cd68b9fd91bb8043dee47015aa63bbdd4fcb06a66c1deca565360fc  0.02497120 : 2323521753 - 2326018872
a6cc9adda0a5c541b21b1f4f0bf5d1cd8e32d8a7afbdfb44a699a49631377cd5  0.00290000 : 2326018873 - 2326308872
aa02a98b2dada8c3e3f5cf1ccc7a2f0ea1cc2cfaecc4e3be4f8df51a92505cb8  0.09997120 : 2326308873 - 2336305992
b6abba202c99971e59021cef44a03904ec847f3344067bea85f8fd12d01678ca  0.00097120 : 2336305993 - 2336403112
b83f1fa87c86f9f1ccfe4050f07d89cd42c9e6670f4ac2a50fb353b626e2cac8  0.14997120 : 2336403113 - 2351400232
b96d2df7cced243d4c729e26698f48e3b6f129120767812ff84e493f5efe8e6b  0.00997120 : 2351400233 - 2352397352
c27881c210b492468a5ae6344f55960f683ac29aa3a275c8f2d524fce763707f  0.00283020 : 2352397353 - 2352680372
d0680226592913af48e6d8e934cdfa931125a2f790a1b416e7bf3c9d1114062c  0.00219435 : 2352680373 - 2352899807
ddbb43f5cad891a5938a2e9764fd450bb96e8c97b02004147b3abcde38e49ad6  0.00300000 : 2352899808 - 2353199807
e6b98443e0c869ef64c28ea6f88b3aed31c9ff8873640c849dca76038c188173  0.01000000 : 2353199808 - 2354199807
e8787010b58516976f0a5265d619ace80f407d0bdb369cfb4531cab606de3437  0.00030000 : 2354199808 - 2354229807
f26019e9dbdc23d3ef57177ffd511175ce5898204306ca500d0e1525a0ee6402  0.01987120 : 2354229808 - 2356216927
f261e94b28a953b44068679e76aaa1cf66a1a2740505616d3508d4b4c0e41464  0.04997120 : 2356216928 - 2361214047
f76c2e724c57313478d4d69c81d7515f9951256a74d786c94ec221b3ad91addf  0.07777777 : 2361214048 - 2368991824
fd1b7b53ca97a676f2db025a5ba2574c05d7603002e95520b3ddca327676325c  0.00030000 : 2368991825 - 2369021824
fef4b4696a1aa17caef79c06caff67f86bbcfa7616d39b44d0bf10a9b3169951  0.00984774 : 2369021825 - 2370006598

modulo 2370006599

Can anyone confirm or deny that?

Edit: https://www.pevpot.com/draws/1 shows the wrong block?



It should link to the xxx006 block, right?

Also, "1 blocks":

[NLNico]

Actually I just concluded that based on:

PBKDF2 is defined as PBKDF2(PRF, Password, Salt, iterations, dkLen) which I'll use as PBKDF2('sha256', BLOCK_HASH, 'pevpot', 10000000000, 32)

The fastest implementation I could find was openssl, which when compiled with -O3 took about 2h47m to run. With the fastest virtual machine I could get my hands on (c4.8xlarge), I got it running in about 2h1m.

Since it's 5B instead of 10B, I figured it's around 1 - 2 hours.