Arielle Lotto - a simple weekly bitcoin lottery I made. Try it out for bits.

[ariellelotto]

http://ariellelotto.com/

Hey all. Long time lurker, first time posting here.

I wrote the server and website here for a weekly Bitcoin lotto. It works like this: submit some bits, your chances for winning each Saturday will be based upon how much you send compared to everyone else. All sent bits are public (both on the website visually and of course on the blockchain). Winning addresses are public too, of course.

One problem I've been having is on how to gain trust from users on the site. I posted on r/bitcoin and instantly got shut down with people talking about their bad experiences with the dicks running schemes before.

Any ideas on how I can make the site even more transparent than it already is? Any other suggestions in general? I'm very open to input.

PS: By the way, the numbers might not line up 100% between the json and the wallet (due to fees, or me just performing tests on the wallet, since this is the first few days of it being operational). The jackpot displayed is an estimate, but you can check against the blockchain to get the real jackpot (whatever the wallet contains minus 5%) if you're super curious. Chances of winning should be accurate, though.

[chrudat]

Impressive work, I'll try it out. The best way to attract players is probably to just advertise by paying trusted forum members.

[pabitel]

I think the inherent problem is that people don't know if the winner will be drawn fairly. Government lotteries, I believe, usually have big auditing firms watching the process. Perhaps if you made the software open source and somehow made the algorithm that selects the winner reproducible.

You may also build some trust if you gave a portion of the proceeds to charity, the way government lotteries do.

[ariellelotto]

I think the inherent problem is that people don't know if the winner will be drawn fairly. Government lotteries, I believe, usually have big auditing firms watching the process. Perhaps if you made the software open source and somehow made the algorithm that selects the winner reproducible.

You may also build some trust if you gave a portion of the proceeds to charity, the way government lotteries do.

Any links to further elaborate/explain how I could create reproducible results? Maybe generating a seed and displaying it, a week before the seed is used on the json to prove who would win based on the current results? Would be kind of weird to be able to just look up the results of a lottery before it's finished, no?

Also, what charity would you recommend? Are there any big-ish ones that accept bitcoin? (The entire lotto is done in bitcoin, it never touches dollars - and I don't plan on letting it to avoid any possible legal issues). I really wouldn't mind (I'd actually prefer) if I could give at least half of the profits to charity, as long as I had enough left over to pay server fees.

[pabitel]

Any links to further elaborate/explain how I could create reproducible results?

Maybe you could somehow generate the seed based on data accumulated from all the entries, such as the average timestamp.

Also, what charity would you recommend? Are there any big-ish ones that accept bitcoin?

http://bitcoin100.org/charities/

[ariellelotto]

...

Maybe you could somehow generate the seed based on data accumulated from all the entries, such as the average timestamp.

This is a good idea. I'm going to work on this and figure out something clever to do with it.

...

http://bitcoin100.org/charities/

Thanks. I'm going to see if I can get it setup to send most of the profits to charities listed on here. Probably places like Wikileaks, Wikipedia, Khan Academy, and anywhere else that deals with the preservation or advancement with the internet or math in general.

[coinableS]

I think the inherent problem is that people don't know if the winner will be drawn fairly. Government lotteries, I believe, usually have big auditing firms watching the process. Perhaps if you made the software open source and somehow made the algorithm that selects the winner reproducible.

You may also build some trust if you gave a portion of the proceeds to charity, the way government lotteries do.

Any links to further elaborate/explain how I could create reproducible results? Maybe generating a seed and displaying it, a week before the seed is used on the json to prove who would win based on the current results? Would be kind of weird to be able to just look up the results of a lottery before it's finished, no?

Also, what charity would you recommend? Are there any big-ish ones that accept bitcoin? (The entire lotto is done in bitcoin, it never touches dollars - and I don't plan on letting it to avoid any possible legal issues). I really wouldn't mind (I'd actually prefer) if I could give at least half of the profits to charity, as long as I had enough left over to pay server fees.

Maybe try incorporating with the block hashes. Give a predetermined time the results will be pulled and a upfront predetermined hash everyone can see. 24 hours later or whenever the drawing is grab the latest hash from the most recent block. Now you just need to convert those hashes into integers and then do some math that will spit out a # between 1 and the number of participants that can be assigned to the users who deposit/play.

[ariellelotto]

...

Maybe try incorporating with the block hashes. Give a predetermined time the results will be pulled and a upfront predetermined hash everyone can see. 24 hours later or whenever the drawing is grab the latest hash from the most recent block. Now you just need to convert those hashes into integers and then do some math that will spit out a # between 1 and the number of participants that can be assigned to the users who deposit/play.

The server end is running on bitcoinj. For this first winning the code was just using Java's math.random to generate the seed. Next week and beyond it'll be using something incorporating the blockchain. It looks like I can use the blockchain as a bitcoinj object and hash it, then incriment up by a hundred every iteration as the seed for each number, so we can display proof of results.

Edit, just saw that I won the first one (I threw in $3 of the $8 last week), so I'm a bit disappointed. I just submitted the whopping $8 back into the pool haha. Hopefully somebody else gets it this time. It currently stores the previous winners and stuff on the site but I haven't made a way to view that info yet, so I'll work on that soon.

Edit 2, I've started work on the viewing of last week's winnings (as you can see on the site on the bottom). I found a way to get it to display everything I want. So next week, it'll display the winning time's current Block and hash of the block - with the code to run to prove that the winner was chosen at random. You can see some of that info now, but since it wasn't all available for last week it just shows as blank.

[coinableS]

Edit, just saw that I won the first one (I threw in $3 of the $8 last week), so I'm a bit disappointed. I just submitted the whopping $8 back into the pool haha. Hopefully somebody else gets it this time.

Creator participates in his own centralized lotto.
Creator wins his own centralized lotto.
Returns money to the pot instead of returning it to the players.

[ariellelotto]

Edit, just saw that I won the first one (I threw in $3 of the $8 last week), so I'm a bit disappointed. I just submitted the whopping $8 back into the pool haha. Hopefully somebody else gets it this time.

Creator participates in his own centralized lotto.
Creator wins his own centralized lotto.
Returns money to the pot instead of returning it to the players.

I'd rather just keep putting money back into the pot for someone else to win legit - than to fake results period. I'd like to keep every single win provable, even the test ones in the beginning.

[Kprawn]

It seems as thought the people running the \r\millionairemakers on reddit has got it working 100% and they have gathered some trust with the community.

Only difference being.... millionairmakers are not run as a lottery. You are 100% correct... there has been a lot of fake bitcoin lotto operations and most people got sick of it.

Transparancy with the draw should be your main concern and also providing proof that it is provably fair.

Good luck, you are entering a area where a lot of people got burned previously. 

[ariellelotto]

Good luck, you are entering a area where a lot of people got burned previously. 

I understand that. Transparency is what I'm trying to achieve. I've currently got it programmed up to save all previous lotto .json files (from which the server checks to find a winner) save. The server finds the latest block at the time of the drawing and saves it into a .json, then hashes the block and uses it as the seed (also saved). All I need to do now is get it all to display nicely on the website, and post the code for anyone to run to verify the winner!

It's just about all setup. The website is running right now though, and the winnings are functional (the first drawing was done last saturday, this saturday will be the second drawing). It currently shows sort of test block down on the bottom of the site, to show what it will look like this saturday when the drawing is held.

[ariellelotto]

A new winner was chosen today! Later today I'm going to be posting the source code that determines the winner, so that others can confirm winnings if desired.

Trying to find a way to post it on the site that looks attractive.