Fairness

CasePlanet is committed to ensuring fairness and transparency. To meet this strict requirement, we have developed a cryptographically secure Provably Fair outcome generator. The system allows you, the player, to confirm the results of every game are genuinely random and have not been manipulated by us. You can read on technical aspects or go straight to the Verification Tool and validate your past rolls.

Vocabulary

Let’s start the exploration by introducing some important terms used within the Provably Fair system. The system is based on cryptography, a field of mathematics. Familiarizing yourself with the terminology makes understanding the process much easier.

Outcome

Provably Fair has a purpose. This purpose is to generate an outcome that is fair beyond any doubt. The outcome is the calculated result of the Provably Fair algorithm.

Client seed

To make the outcome fair, the algorithm includes user-provided data in the calculation. Client seed is a random string provided by your browser with each roll. The value is assigned at random locally in your browser. You can change it at any time, giving you the element of control over the roll.

Server Seed

Just as you, the player, have a say in the outcome, so do we. Server seed is a string randomly generated by us, which remains hidden until you decide to request a new one.

Public hash

We can not show you the server seed while it is still active. If we have done so, you could easily set your client seed to generate an unfair outcome. Instead, we calculate a secure hash of the value and present it to you as a public hash. You are able to verify it once the seed is disclosed.

Nonce

Because each server seed and client seed pair can be used multiple times, we use a nonce to ensure each round has a different combination. It is a counter starting at 1 that increments with each unboxing.

The algorithm

Below, you can find an implementation of the algorithm in JavaScript. We believe code representation is the best suit for anyone reading up to this point.

function calculateValue(
  serverSeed: string,
  clientSeed: string,
  nonce: number,
) {
  const updateValue = getSHA256Hash(`${clientSeed}:${nonce}`)
  const hash = getSHA256Hmac(serverSeed, updateValue)
  const integerValue = Number.parseInt(hash.slice(0, 13), 16)
  return integerValue / 2 ** 52
}

function calculateWinningTicket(
  value: number,
  totalTickets: number,
) {
  if (value >= 1) {
    return totalTickets
  }

  return Math.floor(value * totalTickets) + 1
}

function getWinningTicket(
  serverSeed: string,
  clientSeed: string,
  nonce: number,
) {
  const value = calculateValue(serverSeed, clientSeed, nonce)
  return calculateWinningTicket(value, 1_000_000)
}

CASE OPENING

For each unboxing, using a unique combination of client seed, server seed and nonce, a random winning ticket is determined. The ticket number is matched to predefined ticket ranges for the items in the case. The item whose ticket range includes the winning ticket is selected as the result of the opening.

CASE BATTLE

Case Battles are different from case openings. Instead of obtaining the value from players, we use the drand (not to be confused with phone case manufacturer of similar name). When the battle is ready, a future round from quick chain is selected. The randomness value of this round will be used in place of client seed.

Each round in the case battle is assigned a nonce, starting at 1 and incremented for each successive item unboxed.