Provably Fair Games at Flush | Cryptographic Game Verification

Provably Fair Games at Flush | Cryptographic Game Verification

Game	House Edge	Mechanic
Crash	1%	Multiplier climbs until crash; cash out before it stops
Dice	1%	Predict roll above or below a target number
Plinko	1%	Ball drops through pegs to multiplier slots
Mines	1%	Reveal safe tiles on a grid, avoid hidden mines
Hilo	1%	Predict if next card is higher or lower
Limbo	1%	Set a target multiplier and bet it hits before crash
Balloon	1%	Pump a balloon and cash out before it pops

Provably fair is the most transparent fairness model available in online gambling. Every result from every Flush Originals game can be verified independently by the player, no trust in the casino required, no auditor to believe, no black box. The mathematics are public. The verification takes seconds. This page explains how the system works, which games at Flush use it, and how to verify any past round yourself.

What Provably Fair Means

Traditional online casino games work on a trust model: the casino generates a random result, tells you what it was, and you trust that the number is genuine. The casino might be audited by a third party like eCOGRA or GLI, which provides an additional layer of trust, but you’re still trusting the auditor’s assessment of the casino’s internal systems.

Provably fair replaces trust with mathematics. Before you place a bet, the casino commits to the game outcome using a cryptographic commitment scheme. You receive proof of that commitment before you wager a single cent. After the round, the casino reveals the underlying seed, and you can independently verify that the result matches, using nothing but publicly available tools.

The critical property is that the casino cannot change the outcome after seeing how you bet. And equally, the casino cannot reverse-engineer a favorable seed before showing it to you, because your own random input, the client seed, is part of the outcome calculation. Neither party can manipulate the result. This is not a policy. It is a mathematical constraint.

The Technical Mechanism

The provably fair commitment scheme works as follows. Before your session begins, the casino generates a random server seed, a long random string. The casino immediately hashes this seed using SHA-256 (a one-way cryptographic function) and provides the resulting hash value to you. This is the commitment: the casino has locked in the seed, and the hash proves it without revealing the seed itself.

You then provide your own client seed, a random string you control. You can change this at any time before a round. The game outcome is deterministically generated by combining the server seed, your client seed, and a nonce (a number that increments with each round). The same inputs will always produce the same output, this is what makes verification possible.

After the round, or after you change seeds, the casino reveals the plaintext server seed. You can verify two things: first, that the SHA-256 hash of the revealed seed matches the hash you were given before the round (proving the casino didn’t change the seed). Second, that running the revealed seed + your client seed + the nonce through the published outcome algorithm produces the exact result recorded in your game history. If both checks pass, the round is proven fair.

Flush Originals: The Provably Fair Game Catalog

Flush Originals is the collection of in-house games built specifically for the Flush platform, all using provably fair verification and all carrying a 1% house edge. Each game uses the same underlying commitment scheme described above, the difference between them is purely in how the seeded outcome translates to gameplay.

Crash generates a multiplier that climbs from 1x upward. The seeded outcome determines the crash point, the multiplier at which the round ends. You must cash out before that point. Dice generates a roll between 0 and 99.99, and you win by correctly predicting whether the roll falls above or below your chosen threshold. Plinko drops a ball through a grid of pegs and the seeded outcome determines which multiplier slot it lands in.

Mines presents a grid of tiles, a set number of which conceal mines. The seeded outcome determines mine positions. You reveal tiles to accumulate a growing multiplier, cashing out before hitting a mine. Hilo draws cards in sequence, and the seeded outcome determines each card value. Limbo and Balloon are variations on the Crash mechanic, Limbo lets you pre-set a target multiplier, Balloon lets you inflate a balloon and cash out before it pops. All seven are available directly through your Flush account, playable with Bitcoin or any supported cryptocurrency.

How to Verify a Past Round

Verification requires four pieces of information: the server seed (revealed after the round or after you rotate seeds), the client seed you were using at the time, the nonce for that specific round, and the published outcome algorithm for the game you played. All of this is available in your game history.

Go to your game history in the Flush Originals game you want to verify. Locate the round, each round shows the server seed hash (visible before the round), and after the round or seed rotation, the revealed plaintext seed. Combine the plaintext server seed, your client seed, and the nonce using the published algorithm. The result should match the recorded game outcome exactly.

No coding experience is required. Flush provides a verification interface within the game UI that handles the cryptographic steps, requiring only that you supply the seed values. For players who prefer independent tools, the SHA-256 hash check can be run through any standard cryptographic utility available online. The outcome algorithm is published openly in the Flush Originals documentation.

Provably Fair vs Certified RNG

Third-party slot games at Flush, titles from Pragmatic Play, NetEnt, NoLimit City, and other providers, use a different fairness model. Their random number generators are certified by independent testing laboratories including eCOGRA and GLI. These labs audit the RNG implementation, verify it meets statistical randomness standards, and issue certification. This is the industry standard for licensed slot games.

The certified RNG model is a chain of trust: you trust the certification lab, which trusts the casino’s RNG implementation. That is two links in the trust chain, each of which could in theory be compromised or inaccurate. Certification reviews happen periodically, not on every individual round.

Provably fair requires only one thing: trust in mathematics. The SHA-256 hash function is publicly audited by the global cryptography community. The outcome algorithm is open. The verification is instantaneous and per-round, not periodic. For players who want maximum certainty about game fairness, provably fair is the more rigorous model. The tradeoff is game variety, provably fair is most naturally suited to simple-mechanic games like Crash, Dice, and Plinko. Complex third-party slots are better served by the certified RNG model that the industry has built around them. Flush offers both.

Flush accepts deposits in BTC, ETH, USDT, TRX, and SOL with no conversion fees, instant crediting, and zero-fee withdrawals to your personal wallet.

Related Pages at Flush

Explore more guides and game reviews related to this topic:

• Limbo Review & Free Demo, provably fair multiplier game with adjustable target and instant results
• Mines Review & Free Demo, provably fair grid game where you navigate a minefield for increasing multipliers
• HiLo Review & Free Demo, provably fair card prediction game with selectable risk levels
• Plinko Review & Free Demo, provably fair ball-drop game with peg board multipliers
• Balloon Review & Free Demo, provably fair pump-and-cash-out game with real-time risk escalation
• What Is RNG?, how certified random number generators work in traditional casino slots
• Crash, guide to the crash game format, strategy, and how provably fair applies to it

FAQ

What is provably fair? Provably fair is a cryptographic system where every game outcome can be independently verified by the player. The casino commits to a random seed before you bet, your own seed is combined with it, and the result is deterministically generated. You can verify the casino didn’t manipulate the outcome, no trust required.

How do I verify a provably fair result? In your game history, locate the round you want to verify. Find the server seed (revealed after the round), the client seed you provided, and the nonce. Run these through the published hash function. The result should match the recorded game outcome exactly. Flush provides a verification interface within the game UI.

Can the casino cheat in a provably fair game? No. Because the casino commits to the server seed hash before you bet, they cannot change it after seeing your client seed. Your client seed prevents them from pre-selecting a favorable server seed. The math makes manipulation impossible, not just unlikely.

What is a server seed? A server seed is a random string generated by the casino before each round or session. The casino hashes it with SHA-256 and provides that hash to you before you bet. After the round, the casino reveals the plaintext seed. You verify the hash matches, confirming the seed was set before your bet and not changed afterward.

Which games at Flush are provably fair? All Flush Originals use provably fair verification: Crash, Dice, Plinko, Mines, Hilo, Limbo, and Balloon. Every result in these games is independently verifiable. Third-party slot games at Flush use certified RNG audited by testing labs.

Is provably fair better than certified RNG? Provably fair is more transparent. Certified RNG requires trusting an auditor who trusts the casino, a two-link trust chain. Provably fair requires trusting only mathematics, the algorithm is public, verification is instant, and no third party is involved.

What is Flush Originals? Flush Originals is the collection of in-house games built by Flush, Crash, Dice, Plinko, Mines, Hilo, Limbo, and Balloon. All use provably fair cryptographic verification, all carry a 1% house edge, and all are designed specifically for Bitcoin and crypto gameplay.

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Play responsibly. Even with provably fair games, all gambling carries financial risk. Set strict limits and never wager more than you can afford to lose. Visit BeGambleAware.org for support.

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SHA-256 Hash Functions: The Technical Foundation

The entire provably fair system rests on one cryptographic primitive: the SHA-256 hash function. Understanding it at a practical level demystifies why the system works.

SHA-256 (Secure Hash Algorithm 256-bit) is a one-way mathematical function. Feed it any input, a string of characters, a seed value, any data, and it produces a fixed 64-character hexadecimal output called a hash or digest. The critical properties are:

Deterministic: The same input always produces the same output. SHA-256("flush_seed_example") will return the identical hash on any computer anywhere in the world, every time.

One-way: Given a hash output, it is computationally infeasible to reverse-engineer the input. The world’s fastest supercomputers cannot find a SHA-256 preimage in any practical timeframe. “One-way” is not a marketing phrase, it is a mathematical property that underpins global financial cryptography, HTTPS connections, and Bitcoin itself.

Avalanche effect: Changing one character of the input changes approximately 50% of the output bits. You cannot make small changes to a seed to produce a specific target hash, small input changes produce completely unpredictable output changes.

No collisions (practical): Two different inputs producing the same SHA-256 hash output has never been demonstrated despite decades of global cryptographic research. You cannot fake a seed by finding a different one that produces the same hash.

These properties together create the commitment scheme. When Flush shows you a server seed hash before your round, they have mathematically locked themselves into that seed, they cannot change it without producing a different hash that you would detect. This is not trust. It is cryptography.

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Server Seed vs Client Seed: Roles and Responsibilities

The two-seed system in provably fair gambling serves a specific purpose: preventing either party from controlling the outcome alone.

Server Seed: Generated by the casino before each session or seed rotation. The casino provides its SHA-256 hash to the player before the first bet. The seed is hidden until after the round or until the player rotates seeds. It ensures the casino commits to outcomes in advance.

Client Seed: Generated by the player’s browser by default (typically a random hex string). The player can change it at any time before a round. The client seed is visible to the player and to the casino. Its purpose is to ensure the casino cannot predict the final outcome with certainty, even if the server seed is fixed, the casino cannot know the client seed the player will use, preventing pre-computation of favorable seeds.

Nonce: A counter that increments with each round played using the same seed pair. The nonce ensures each round within a seed pair produces a unique outcome even if the seeds remain the same.

The combined formula: outcome = f(HMAC-SHA256(server_seed, client_seed + ":" + nonce)) where f is the game’s published outcome algorithm. Every round is uniquely determined by all three inputs, and neither party can manipulate the combination without the other detecting it.

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Cryptographic Proof Example: Verifying a Dice Round

Here is a complete worked example of verifying a provably fair Dice round using real verification logic.

Assume the following values:

• Revealed server seed: a3f8b9e1c2d4... (64 hex characters)
• Client seed: 7e4d2f1a9c8b...
• Nonce: 42

Step 1, Verify server seed commitment: Run SHA-256(a3f8b9e1c2d4...) and confirm the result matches the hash shown to you before the round began. If it matches, the casino committed to that seed before your bet.

Step 2, Compute the outcome hash: Calculate HMAC-SHA256(a3f8b9e1c2d4..., 7e4d2f1a9c8b...:42). This produces a 64-character hex hash.

Step 3, Convert to game outcome: For Dice, take the first 8 characters of the hash (a 32-bit hex value). Interpret as an unsigned integer. Divide by 2^32. Multiply by 10,001 (the dice outcome range is 0.00 to 100.00 with two decimal places). The result is your dice roll.

Step 4, Match against game history: If the calculated roll matches the result recorded in your game history for round 42 with that seed pair, the round is verified fair.

Any player can perform these calculations using standard tools, a SHA-256 calculator, a hex-to-integer converter, and basic arithmetic. No programming experience is required for simple verification. Flush’s built-in verifier handles all steps automatically and shows you each intermediate value.

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Which Flush Games Are Provably Fair

Provably fair verification applies to all Flush Originals, the seven in-house games built specifically for the Flush platform. Third-party games from external studios use certified RNG instead.

Provably fair (Flush Originals):

Game	Mechanic	How Outcome Maps to Result
Crash	Multiplier climbs until crash	Hash output determines crash multiplier
Dice	Roll 0–99.99	Hash output maps to roll value
Plinko	Ball drops through peg grid	Hash determines which multiplier slot
Mines	Hidden mines on grid	Hash determines mine positions
Hilo	Higher or lower card sequence	Hash determines each card value
Limbo	Target multiplier bet	Hash determines if target is reached
Balloon	Pump and cash out before pop	Hash determines pop point

Certified RNG (third-party slots and live games): All games from providers including Pragmatic Play, NetEnt, NoLimit City, Evolution Gaming, and 25+ other providers at Flush use certified RNG audited by independent testing laboratories. Their fairness is verified by auditors; it is not player-verifiable on a per-round basis.

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Why Provably Fair Is Stronger Than RNG Audits

RNG audit certification and provably fair are both legitimate fairness models, but they operate at different trust levels.

RNG audit certification (eCOGRA, GLI, BMM, iTech Labs) involves a testing laboratory reviewing the casino’s RNG implementation, examining the code, the statistical output distribution, and the integration with game logic. The lab issues a certificate stating the RNG meets randomness standards. Audits happen periodically (quarterly, annually) rather than on every individual round.

Trust chain for certified RNG: You trust the testing lab’s assessment → which trusts the casino’s submitted code → which may or may not reflect the live production system exactly. If the casino runs different code in production than what was audited, no player would know. If the testing lab made a procedural error, no player would know. Two links of trust, neither verifiable by the player on a per-game basis.

Provably fair trust chain: You trust SHA-256 cryptography → a function with decades of global public scrutiny, underpinning Bitcoin and global internet security → verified on every individual round by any player using publicly available tools.

Provably fair eliminates the auditor link entirely. You do not need to trust Flush’s word, a certification logo, or a third-party lab. You verify the mathematics yourself. The SHA-256 function is the most-scrutinised cryptographic primitive in existence, its security is the consensus of the global cryptography community, not a single auditor’s sign-off.

The practical tradeoff: provably fair is best suited to games with simple outcome structures (a number, a multiplier, a grid of positions). Complex third-party slots with thousands of symbol combinations, cascading wins, and multi-level bonus systems are more naturally served by the certified RNG model. Flush provides both depending on the game category.

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Additional FAQ

How do I change my client seed at Flush? In any Flush Originals game, go to the fairness settings, typically accessible via a shield or fairness icon in the game interface. You will see your current client seed and can enter any custom string. Changing the client seed automatically rotates the server seed, the old server seed is revealed at the moment of rotation for verification.

What is a nonce and why does it increment? The nonce is a round counter that starts at 1 for each seed pair and increases by 1 with each round played. It ensures each round within a seed pair produces a unique outcome. Without the nonce, every round with the same seed pair would produce the same result, the nonce provides per-round uniqueness while maintaining full verifiability.

Can I set my own server seed? No. The server seed is generated by Flush’s servers. You control the client seed. The two-party structure is deliberate, if you could set the server seed, you could pre-compute favorable outcomes. If the casino set the client seed, they could do the same. The split responsibility is what makes provably fair work.

Is SHA-256 actually secure? SHA-256 is the hash function used in Bitcoin’s proof-of-work system and in TLS certificates securing global HTTPS traffic. It has been subjected to continuous public cryptanalytic scrutiny since its publication by NIST in 2001. No preimage or collision attack has ever been demonstrated. It is the most battle-tested cryptographic hash function in existence.

Do I need to verify every round? No. Provably fair means you can verify any round, not that you must verify every one. Most players verify occasionally to confirm the system works as described, then proceed with confidence. You can verify any historical round at any time; game history preserves all required seed values.

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Play responsibly. Even with provably fair games, all gambling carries financial risk. Set strict limits and never wager more than you can afford to lose. Visit BeGambleAware.org for support. GamCare resources available at gamcare.org.uk.