Topic: Primedice.com | Since 2013 | Longest Running Crypto Casino | 113 BTC Jackpot! - page 1284. (Read 1991083 times)

I don't know if it's that clear cut. If you launch a site with the documentation saying "we are provably fair because we do A, B, C to generate your rolls" but what you actually do is "A, B, D", then when the outcome of A, B, C and A, B, D differ, such that the player would have won if you did what you said you were going to do, but he loses because you actually do something different... then it seems like he has a winnable case there.

He took you at your word that you were doing A, B, C but it turned out you weren't doing that at all, and the difference caused him to lose.


I think the code snippet was updated recently. It was just updated wrongly, making it even worse than before since now it often computes very low rolls, like the 00.02 in the case that brought the error to light.

I don't know if it's that clear cut. If you launch a site with the documentation saying "we are provably fair because we do A, B, C to generate your rolls" but what you actually do is "A, B, D", then when the outcome of A, B, C and A, B, D differ, such that the player would have won if you did what you said you were going to do, but he loses because you actually do something different... then it seems like he has a winnable case there.

He took you at your word that you were doing A, B, C but it turned out you weren't doing that at all, and the difference caused him to lose.


I think the code snippet was updated recently. It was just updated wrongly, making it even worse than before since now it often computes very low rolls, like the 00.02 in the case that brought the error to light.

I'm sorry for the lack of update in documentation, I was told this was updated probably about three times now but apparently it has not changed. I do not have a strong understanding of provably fair and will poke our main dev to resolve this today.

No, you aren't understanding:


Every bet was unfair, not only the 9,900x multiplier ones.

For example:

To win <49.5 you had to roll <49.495000 to beat the unfair rounding, and so only had a 49.495% chance of actually winning.

Similarly, to win >50.5 you had to roll >= 50.505000 to beat the unfair rounding.

Every bet on the site had a 0.005% smaller than advertised chance of winning.

I believe the first time I had heard of the rounding issue was after the launch of PD3 and one of our developers immediately said that was incorrect. However, I will be having a conversation with our developers and bring up the points you responded with as they do seem valid.

If only verification documentation is wrong what it seems to be than i guess its not that bad situation ?

I think dev has that already updated but as i said he wasn't online for whole day , he shoulda pushed some other updates today also .

OK, so it's a different situation.

At PRC dice they designed a bad provably fair algorithm that rolled 'high' too often, implemented the bad design perfectly, someone discovered it, exploited it, profited, but wasn't allowed to withdraw.

At PD here the provably fair algorithm was bad during beta, I pointed it out, they fixed it, but didn't update the documentation or the verification script. I pointed that out and they tried to fix the verification script but got that wrong.

So PRC had a bad design, correctly implemented and correctly documented.
PD had a good design, correctly implemented but poorly documented.

I expect Stunna would argue that the site is working as intended, that only the documentation is wrong, so "suck it". Except he'd use better words.

OK, so it's a different situation.

At PRC dice they designed a bad provably fair algorithm that rolled 'high' too often, implemented the bad design perfectly, someone discovered it, exploited it, profited, but wasn't allowed to withdraw.

At PD here the provably fair algorithm was bad during beta, I pointed it out, they fixed it, but didn't update the documentation or the verification script. I pointed that out and they tried to fix the verification script but got that wrong.

So PRC had a bad design, correctly implemented and correctly documented.
PD had a good design, correctly implemented but poorly documented.

I expect Stunna would argue that the site is working as intended, that only the documentation is wrong, so "suck it". Except he'd use better words.

Looking to maybe add a form of "Rake back" to Primedice.

This would mean if you wager a certain amount the house edge would be lowered. Here's an example:

 - User A has a total wagered 50 BTC. He then receives 0.1% of all his bets back (Win or lose) - Making house edge 0.81
 - User B wagered of 200 BTC. He then receives 0.2% of all his bets back (Win or lose) - Making house edge 0.71
 - User C had a total wagered of 1,000 BTC. He then receives 0.3% of all his bets back (Win or lose) - Making house edge 0.61

Sound good?

See the screenshots below. I did verify all 11 bets. All 10 bets are correct, but the No.2 bet from top is wrong.
On the screenshot, the roll is 92.29. However, the result I got from script is 0.02.
So I should win that bet, there would not be the last one bet(top one) which cleared me out.

First five characters are taken from the hex string to create a roll number that is 0-1,048,575. If the roll number is over 999,999, the proccess is repeated with the next five characters skipping the first one.

Happy to know it's not just me. Waiting for explanation please. 

That has happened with me as well. Says three refs but only two show up.

Primedice is cheating

Today I was just using PD to bet and doing the double-or-nothing experiments.
It was going fine at first. But suddenly, I had 11 consecutive-losing bets.
They were pretty odd, weren't they?
So I did some verification using the script provided by Primedice.

See the screenshots below. I did verify all 11 bets. All 10 bets are correct, but the No.2 bet from top is wrong.
On the screenshot, the roll is 92.29. However, the result I got from script is 0.02.
So I should win that bet, there would not be the last one bet(top one) which cleared me out.

BET #805607190 INFO

SERVER SEED (REVEALED)
41fa224237f452360db8d35a276f4067fce6cad8d3dbf3c73bde2e804c8cb8c7
CLIENT SEED (NONCED)
ca45edd88ef251dd43edf42dc97c7ffb-3391

Screenshot of 11 consecutive-losing bets
http://prntscr.com/4ed9mo

Screenshot of BET #805607190 INFO
http://prntscr.com/4eda18

You can look up these bets by the bet id shown in the screenshot and verify them by yourself.
This did not just happen once but twice today and almost clear me out.
Since Primedice has been online for so long, I could not imagine how many times it has cheated.
I probably will do the same experiments on other bitcoin gambling web site. But Pirmedice is not trustworthy and return my bitcoin.

I also found the possible unfair when you PVP with "strangers" on Primedice.
See the post: https://bitcointalksearch.org/topic/m.8315850


The script I am using:

            //the seed pair itself
            var clientSeed = "ca45edd88ef251dd43edf42dc97c7ffb"; //dont forget to exclude the dash and the nonce!
            var serverSeed = "41fa224237f452360db8d35a276f4067fce6cad8d3dbf3c73bde2e804c8cb8c7";

            //bet made with seed pair (excluding current bet)
            var nonce      = 3391;

            //crypto lib for hmac function
            var crypto = require('crypto');

            var roll = function(key, text) {

                //create HMAC using server seed as key and client seed as message
                var hash = crypto.createHmac('sha512', key).update(text).digest('hex');

                var index = 0;

                var lucky = parseInt(hash.substring(index * 5, index + 5), 16);

                //keep grabbing characters from the hash while greater than
                while (lucky >= Math.pow(10, 6)) {
                    index++;
                    lucky = parseInt(hash.substring(index * 5, index + 5), 16);

                    //if we reach the end of the hash, just default to highest number
                    if (index + 5 == 128 + 1) {
                        lucky = 99.99;
                        break;
                    }
                }

                lucky %= Math.pow(10, 4);
                lucky /= Math.pow(10, 2);

                return lucky;
            }
            console.log(roll(serverSeed, clientSeed+'-'+nonce));

Looking to maybe add a form of "Rake back" to Primedice.

This would mean if you wager a certain amount the house edge would be lowered. Here's an example:

 - User A has a total wagered 50 BTC. He then receives 0.1% of all his bets back (Win or lose) - Making house edge 0.81
 - User B wagered of 200 BTC. He then receives 0.2% of all his bets back (Win or lose) - Making house edge 0.71
 - User C had a total wagered of 1,000 BTC. He then receives 0.3% of all his bets back (Win or lose) - Making house edge 0.61

Sound good?

Also, on the affiliate dashboard it says I have 5 referred users but there are only 4 listed below that.  Explanation please?

Looking to maybe add a form of "Rake back" to Primedice.

This would mean if you wager a certain amount the house edge would be lowered. Here's an example:

 - User A has a total wagered 50 BTC. He then receives 0.1% of all his bets back (Win or lose) - Making house edge 0.81
 - User B wagered of 200 BTC. He then receives 0.2% of all his bets back (Win or lose) - Making house edge 0.71
 - User C had a total wagered of 1,000 BTC. He then receives 0.3% of all his bets back (Win or lose) - Making house edge 0.61

Sound good?