Show HN: Anonymous Bitcoin Lottery

https://www.btc-l.com

by Prefinem • 13 years ago

35 51 13 years ago

btc-l.com

tocomment3• 13 years ago

Really cool! Can you give a rough sketch of the aritechure?

Are you using an API for do you code right to the bitcoin protocol?

Prefinem19• 13 years ago

I run bitcoind --daemon and use the bitcoin API through JSON RPC. So, the website connects to the server and pretty much has complete access.

tocomment3• 13 years ago

I'd say to add some more instructions, especially on the play page. E.g., "send X bitcoins to this address to play in this game", etc.

Also on the front have a live "paid out today" widget.

tocomment3• 13 years ago

Actually under the paid out today number you could have a little hyper link that says "verify" and links to the blockchain showing the actual payouts. It might give you some legitimacy.

Prefinem19• 13 years ago

Thanks for catching this.

olalonde• 13 years ago

There are already at least hundreds of bitcoin lotteries and casinos, most of which are probably scams (see bitcointalk.org forums). How do you plan to differentiate?

jff• 13 years ago

Why differentiate? Scams are apparently more profitable, or else these bitcoin lotteries would be running legit instead.

pampa• 13 years ago

there is one problem. you usually cant run a lottery, unless you are government, or a government affiliated company

Prefinem19• 13 years ago

I have seen a lot of different one while I was researching, but most all seemed scam-ish. I honestly wanted one that wasn't a scam.

As far as different, I am not sure other than actually doing what the site says it will do.

iaw• 13 years ago

I've been working on a BTC Raffle site also although I'm targeting lower fees and plan on making it provably fair.

Good job.

Prefinem19• 13 years ago

I have dropped the fees to help early adopters. If you are interested in how this works, send me an email: prefinem@gmail.com

seanalltogether2• 13 years ago

On your lottery page, I initially thought the addresses listed in the grid were the ones to send bitcoins to. You should really consider laying out that page differently to avoid confusion.

Prefinem19• 13 years ago

I would love to hear suggestions.

seanalltogether2• 13 years ago

The problem I think is that the bitcoin address to send money to looks like its part of the table header description. So you naturally gloss over it and focus your attention on the table data.

benjoffe• 13 years ago

> Currently the lottery has a 25% cut of the total amount in the lottery. This is used to pay for development, server costs and maintainence. Eventually, my goal is to decrease the fee to as small as possible to allow for the largest winning. This will take place when the development stops (meaning there are no features to be added) and/or the lotteries take place more often.

I find this to be backwards, you are effectively punishing your early adopters. It seems to make much more sense to make the cut lower (or zero) now, and increase it later when you have more users.

Prefinem19• 13 years ago

I like your idea. I will cut the fees to something like 1% to pay for the transaction fees

shloime• 13 years ago

Good call.

jswift• 13 years ago

It's a good idea but any cut above this will make the lottery very expensive. National lotteries can pay out 50% because they have a monopoly and the remainder usually goes towards a community project.

TheTaytay2• 13 years ago

You probably haven't updated it yet, but on one page it says 1%, and on the other it says 25%.

jaredandrews• 13 years ago

I noticed you have changed your fee. The example in how it works still reflects the old rate. Just letting you know. Nice project BTW I'll give it a shot next time I get some BTC.

tptacek• 13 years ago

How poetic.

crntaylor• 13 years ago

The implementation is really simple. Buy 1 BTC at current prices. Wait a year. Now your 1 BTC is either worth 1000x as much (with low probability) or nothing (with high probability). Instant lottery!

shocks• 13 years ago

You should make this provably fair...

grimtrigger• 13 years ago

http://cstheory.stackexchange.com/questions/11722/a-lottery-...

Prefinem19• 13 years ago

If I could prove the fairness (paying out to the winner) without compromising anything, I would. If you know of a way, I would be more than willing to do so.

TheTaytay2• 13 years ago

I couldn't figure out how long the current lottery was going to run. I didn't see what the target # of tickets sold was for this first round, so I didn't know what the estimated date of the first drawing was.

Prefinem19• 13 years ago

The target is 1BTC in the pool, I have posted under the lottery table when a winner will be selected.

jimrandomh2• 13 years ago

And the winner is... Anonymous Coward 961! Who is absolutely not the operator's secret alter-identity! Now if you'll excuse me, this yacht won't buy itself.

I don't know whether this is actually a scam, but you need to put a considerable amount of work to make into making it not look like one. As it is, I see: disposable identity, Bitcoin, and a straightforward opportunity to steal without getting caught.

Prefinem19• 13 years ago

Of course, you could just watch who the payment is made out to and verify if the owner is the winner. I could show the selection method of the winner and show that it is a random generator that grabs the winner. Either way, its still a gamble. If you don't trust the site (or me) then you won't trust any of the code I post to show the random selection of the user.

mcherm4• 13 years ago

See my post lower-down: https://news.ycombinator.com/item?id=5566144

Prefinem19• 13 years ago

I have implemented a system that adds verification. You can read about it here: https://www.btc-l.com/about#verification

jimrandomh2• 13 years ago

This is progress, but it doesn't look done yet - you need to explain how someone would perform the verification, and why prior knowledge of the seed won't let someone manipulate the results by placing strategic bets.

nbdbvcrea• 13 years ago

I like SatoshiDice more.

It's "provably trustworthy" and you can adjust price multiplier from 1.004x to 64000.000x.

IanCal• 13 years ago

Please check the legal implications of this. I know that you can't run a lottery in the UK unless you're a charity.

tzs• 13 years ago

I'm curious--how many here would work on this kind of project? I'd love to from an engineering point of view. It would be quite fun.

However, I suspect it will be a net detriment to its typical user, and don't see any real benefits to counteract that, so would have trouble working on such a thing due to the moral issues. People who like to gamble and are able to do so responsibly already have plenty of easy outlets in which to indulge their hobby. It seems to me that this service will disproportionally attract people who have a gambling problem, and I'd feel quite troubled helping with that.

Prefinem19• 13 years ago

Just to send out an update on the site. Fixed quite a few issues today. Thanks for the help everyone. One of the big things was changing the fee to 1% to help pay any transaction fees and make sure early adopters win almost all of the lottery. Another was the incorrect display of # of tickets purchased and amount of bitcoin in the pool. This has been fixed with no loss of data and there is now more bitcoin showing up in the pool.

v-1971• 13 years ago

Here is an alternate algorithm, based on mcherm's suggestion. Choose a publicly available number, such as NYSE closing price, that is not revealed until after the lottery closes. The hash of this is the target. The exact format of what is hashed is announced in advance.

All purchasers' bitcoin addresses are posted publicly, in the order they come in. They are salted with the ticket number, i.e. mybitcoinaddress-001 represents the first ticket I bought. All of these addresses (including salt) are hashed. The one that is closest to the target is the winner. Closeness can be measured as integers (absolute value) with ties possible but extremely unlikely.

Show HN: Anonymous Bitcoin Lottery

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