Provably Fair System

Roll Calculation

// Example PHP code to calculate the roll
//
// Assuming you have the server seed, client seed, and nonce

$serverSeed = 'Your server seed here'; // to be generated by the server
$clientSeed = 'Your client seed here'; // can be set by the user
$nonce = 1; // this is a counter that starts at 1 and increments with each case opening

// Hash the server seed to ensure it is not tampered with
$serverHash = hash('sha256', $serverSeed); // hash of the server seed

// Example PHP code to calculate the roll
$hash = hash_hmac('sha512', "{$clientSeed}-{$nonce}", $serverSeed);

// Extracting the first 13 characters of the hash
$hexPart = substr($hash, 0, 13);
$decimal = hexdec($hexPart); 

// Convert to a roll between 0.001 and 100.000
$roll = (($decimal % 100000) + 1) / 1000; // This gives a roll between 0.001 and 100.000

// Your roll
echo "Roll: $roll\n";
                        

// JavaScript roll calculation
// You can run this in browser console

const serverSeed = 'Your server seed here';
const clientSeed = 'Your client seed here';
const nonce = 1;

const crypto = window.crypto || window.msCrypto;

async function calculateRoll(serverSeed, clientSeed, nonce) {
    const text = `${clientSeed}-${nonce}`;

    const enc = new TextEncoder();
    const key = await crypto.subtle.importKey(
        "raw",
        enc.encode(serverSeed),
        { name: "HMAC", hash: "SHA-512" },
        false,
        ["sign"]
    );

    const signature = await crypto.subtle.sign("HMAC", key, enc.encode(text));
    const hashArray = Array.from(new Uint8Array(signature));
    const hashHex = hashArray.map(b => b.toString(16).padStart(2, '0')).join('');

    const hexPart = hashHex.slice(0, 13);
    const decimal = parseInt(hexPart, 16);
    const roll = ((decimal % 100000) + 1) / 1000;

    console.log("Roll:", roll.toFixed(3));
}

calculateRoll(serverSeed, clientSeed, nonce);
                        

Item Selection

Once the roll is calculated, the system determines which item you receive based on the probability ranges:

// Example with 3 items
Item A: 50% chance (0.000 to 50.000)
Item B: 30% chance (50.001 to 80.000)
Item C: 20% chance (80.001 to 100.000)

// If roll = 75.123
// Item B would be selected (as 50.001 ≤ 75.123 ≤ 80.000)
                        

Server Seed Rotation

For enhanced security, server seeds are automatically rotated:

// Server seed rotation rules
1. Each server seed is used for up to 100 case openings
2. After 100 openings, a new server seed is automatically generated
3. When a server seed is revealed, a new one is generated for future openings
4. Each user has their own server seed that is used across all their openings
                        

Nonce Explanation

The nonce is a counter that increases with each case opening:

// Nonce usage
1. Starts at 1 for each new server seed
2. Increments by 1 for each case opening using the same server seed
3. Included in the roll calculation to ensure unique results
4. Allows for verification of multiple rolls with the same server and client seeds