Hello,

Announcing sigmanero.org, a new sports betting exchange website that uses Monero’s multi-sig wallets for each individual bet.

The use of multi-sig wallets should stop concerns about rug-pulls, exit-scams, or wallets becoming compromised by attackers.

In a betting exchange like Sigmanero, users bet against other users and the house earns a commission in each bet.

**The small innovation of sigmanero.org is that multi-sig wallets are auto-generated in the browser of each user, which hopefully significantly reduces the hassle of using multi-sigs. No need for command line interface (CLIs). **

The setup is as follows. User A places an offer for a bet in a particular event for example LA Lakers to win vs Boston Celtics. This offer will have the, side (Lakers or Celtics to win), the amount in XMR and odds that user A would like to bet.

User B can see user A’s offer and accept the offer. At this point, a new 3/4 multi-sig wallet will be created between A, B and Sigmanero.

This new multi-sig will have to funded before the start of the event by both A and B. Both A and B will also need to save their new multi-sig seed keys separately.

When the winner is known, the winning side can reclaim funds using his/her seed key to sign the transfer out of the multi-sig wallet. Important to stress that if they don’t save their seed keys, then they cannot reclaim funds, and there will be nothing Sigmanero can do about it.

At no point in time will Sigmanero have controls of funds or will any of the seed keys be shared with Sigmanero. Sigmanero will have 2 of the 3 necessary keys to sign transfers for extra security and to guarantee that it will always be a party to the transfers. Despite this, Sigmanero will always require one extra signature from one of the users.

For each bet both users will have to have at least 10% of the bet amount as a bounty deposit with Sigmanero. For example if the bet amount is 1 XMR, the user will have to have at least 0.1 XMR deposited with Sigmanero. This will be the only element of custody of funds that Sigmanero will have. However, as soon as the user funds the new bet, the 10% bounty is released which the user can withdraw back from Sigmanero.

The 10% bounty from each user will be used as an incentive for users to fund and commit to their bets with other users. If a user agrees to a new bet but does not fund the new multi-sig wallet with his/her bet amount, then that user will lose the 10% bounty, and 50% of this bounty will be given to the opposite side of the bet, provided that the opposite side has funded its side of the bet.

More details under https://sigmanero.org/info

Because the creation of multi-sig wallets needs synchronisation between users and Sigmanero, when a new bet offer is place by a user, this user cannot leave the page until the bet is accepted by another user or the user decides to cancel the new offer. This is not ideal, however the advantage for the user that makes an offer is that it can set an XMR amount and betting odd according to his/her like, as opposed to simply accepting the terms of existing offers.

To facilitate the coordination between users offering bets and users accepting bets, betting for each event starts only 6 hours before the event and closes 15min before the event start. This element of the user experience might not be ideal, but we hope that the 6 hour window is wide enough to provide flexibility for all, but also small enough to get users all in one place at the same time. The betting window closes 15min before scheduled event times to allow users to fund their multi-sigs.

Hopefully this is a good overview. Please let us know what you think. Feedback at this point is extremely appreciated.

  • jet@hackertalks.com
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    9 months ago

    Interesting concept!

    The use of bounty and deposit interchangeably is a little confusing on the website.

    A infographic explaining the process would be helpful.

    When funding a wager can the deposit be used as part of the funds? (Instead of refunding the deposit, I just fund 90% into the wager wallet and the house moves my 10% into the wager wallet?)

    Rug-pull scenario: is there a way to verify the counterparty wallet signatures? If someone was going to rug-pull they would simply just use their own keys for one side of the bet. Then they would control 3/4 of the multisig wallet keys

    I don’t see where the active bets are listed on the website

    • sigmanero_orgOP
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      9 months ago

      Great points, thank you!

      We will work on a infographic right the way. Agree that deposit/bounty distinction is not clear. -"When funding a wager can the deposit be used as part of the funds? " – this is an interesting suggestion, we will consider adding it at least as an option. One possible downside is that users would need to constantly “top up” their balances with Sigmanero to make additional bets and this can add extra time to the overall process. But if people prefer it, why not.

      -“Rug-pull scenario: is there a way to verify the counterparty wallet signatures?” – the only conceivable “rug-pull” scenario is if us “Sigmanero” decide to place bets as counterparty to users and therefore control 3/4 keys from the start. The incentive to rug-pull is very small because it would tank reputation instantly and the gains from the rug-pull would be limited to one bet at a time that gets stolen. We don’t expect any “wales” to start placing very large bets on the website that would economically justify such an incentive.

      Additionally, we expect each bet to be of modest size because whoever places a new bet also needs to consider that the counterparty needs to be able to match the opposite side. If there are two genuine counterparties in a bet plus Sigmanero, then a rug-pull is impossible.

      Small note: If a user decides to be both parties of the bet (creating 2 accounts in Sigmanero), then he/she would still only have 2/3 necessary keys for the signature in the 3/4 multisig set up. If a user wants to verify that the new multisig wallet is indeed 3/4 set up, then he/she can always recover the wallet locally using Monero CLI and verify that it is indeed 3/4.

      -“I don’t see where the active bets are listed on the website” – at this point only open bets are shown, that is, bets waiting for a counterparty. We will add “total bet volumes” shortly.

      Thanks!