Ninjastic
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Post
Topic
Board Gambling
Re: FreeBitco.in - Win free Bitcoins every hour!
by
wetsuit
on 24/06/2018, 03:40:29 UTC
Quote from: Real14Hero on June 24, 2018, 02:25:57 AM
Quote from: Thirdspace on June 23, 2018, 11:23:09 PM
Quote from: Real14Hero on June 23, 2018, 06:07:00 PM
As no one knows the "Ticket Number" which was alooted to him, the game can be easily riggged.
I'm not sure but I think these "Ticket Number" will be published along with the future bitcoin block number
I will post back here when I found the references,
but probably TheQuin keeps the info handy and can give you links and more details on it

edit: found it, one page back
Quote from: TheQuin on June 22, 2018, 02:23:05 PM
We publish on Twitter a file that contains the number of the block that the hash will provide the client seed. That file also includes the server seed and ticket list. That's everything you need to verify the result.
What I am saying is that the ticket list can be easily manupulated by alloting the winning ticket to such an account that is either held by freebitco.in itself or is inactive since long time(there are thousands of such accounts at regular intervals).

So even if they assort the userids in ascending order and give tickets accordingly, still they have scope left for increasing the number of tickets of their favoured userid to win the lottery.

Tickets are allotted before the bitcoin block is mined and this is timestamped on twitter. We cannot allot any tickets after the block is mined. We have explained all this in the provably fair box in the lottery page:

Quote
HOW IS THE SYSTEM FAIR?

The system described above that is used for picking the winners is provably fair because it has multiple safeguards in place to ensure that winners are picked randomly and fairly.

  • We provide a SHA256 hash of the server seed when a lottery round starts. If we change the server seed at any time, the SHA256 hash of the new seed will not match the hash we provided earlier. After a round has ended and we provide the server seed that will be used to pick winners, the hash of the seed we provide can be checked against the hash we provided originally and both should match.
  • We use a future bitcoin block hash as the "client seed" ie. a seed that we do not know of. All bitcoin block hashes are unique and nobody knows what the block hash of a future block will be until the block has been mined.
  • We use twitter to publish the future bitcoin block number, the list of users and their ticket numbers and the MD5 hash of the user list. It provides a timestamp to check if the block hash that we use is indeed in the future. Since tweets cannot be edited, only deleted - if we delete the tweet after the future block has been mined and publish a new one, it would be easy to catch us cheating by comparing the timestamp of the tweet and that of the bitcoin block. The timestamp of the tweet should always be lesser than the time timestamp of the bitcoin block whose hash is used as the client seed.
  • We provide a MD5 hash of the text file containing the list of users and their ticket numbers. If even a single character in the text file is changed after the MD5 hash in the tweet is published, the MD5 hash of the edited file will not match the MD5 hash provided in the tweet.