The 2024 online gambling market is worth $97.15 billion – and by 2029, it will reach $132.9 billion. But here's the surprise: of the market's 5,000+ platforms, only 12% use a truly transparent system for random number generation.
Most developers believe that RNG (Random Number Generator) equals fairness. But when Legjobbkaszino conducted a technical audit of 180 online casino platforms during 2023-2024, we discovered a shocking pattern: 67% of traditional RNG implementations contained architectural decisions that a player could never independently verify.
This article reveals the technological gap between "fair" and "provably fair" systems – and shows why blockchain-based RNG is changing the game rules.
Why this matters now – especially in Hungary
The Hungarian Gambling Supervisory Authority (SZTFH – Szabályozott Tevékenységek Felügyeleti Hatósága) partially liberalized the Hungarian online gambling market in January 2023. The new regulation allows operators from the EEA to obtain sports betting licenses – but online casino games remain under strict state control.
This means anyone building a platform operating in Hungary today must comply with SZTFH's Decree 5/2021 – which sets specific technical requirements for RNG implementation and auditability.
But there's a bigger question too.
As players become increasingly tech-savvy, the "trust us" approach is no longer enough. Blockchain-based systems have already proven there's a better solution – where players can mathematically verify the fairness of every single game round.
In the next 10 years, this will become the new minimum standard.
Traditional RNG architecture: how the “black box” works
When an average developer hears they need to "implement RNG" for an online casino, they usually think of Pseudo-Random Number Generator (PRNG) algorithms.
The process consists of three main steps.
Seed generation
The system uses an initial seed value – typically the server timestamp combined with some entropy source. On Linux, this is often the /dev/urandom system file, which uses hardware noise to generate randomness. In Windows environments, the CryptGenRandom API serves this purpose.
The quality of seed generation is critical. If the seed is predictable or repetitive, the entire system is compromised. For example, a poor implementation might simply use the current millisecond timestamp – meaning games started in the same millisecond get the same seed.
The algorithm
The most popular choice is Mersenne Twister – a fast, high-quality PRNG algorithm widely used in game development and simulations. But in the casino industry, Cryptographically Secure Pseudo-Random Number Generators (CSPRNGs) are more common, such as Node.js's crypto module or Python's secrets library.
The difference? Mersenne Twister isn't cryptographically secure – theoretically reversible by observing generated numbers. CSPRNGs, however, use algorithms (like AES in CTR mode or ChaCha20) that are unbreakable even for nation-states.
The output
The algorithm generates a number sequence that appears statistically random. On a slot machine, for example, this determines which symbol appears in which position. The system generates a large number, then maps it to the game's valid range using modulo operation – for instance, a number between 0 and 2 billion modulo 37 gives the roulette wheel number.
But here comes the problem.
Critical weaknesses of traditional RNG
1. Zero transparency
Players never see the seed, the algorithm, or the specific implementation. They only see what the server shows them – and must blindly trust that the server isn't manipulating anything.
Tibor's personal experience from 2022: we tested a platform where developers "forgot" to update the seed every game round. The result? Gameplay followed a completely predictable pattern for 100 rounds. Players noticed, exploited it – and the casino lost 2.4 million HUF in one weekend before they noticed the bug.
This wasn't malicious intent. It was human error in a black box system.
2. Server-side control
Since all logic runs on the server, the casino could theoretically modify the seed, the algorithm, or even post-process the output without the player's knowledge.
Yes, independent auditors exist – eCOGRA, iTech Labs, BMM Testlabs – who verify these systems. But these audits often happen only once or twice a year. What happens between audits?
The answer: no guarantee.
3. Post-hoc manipulation possibility
In classic RNG architecture, the output is generated when the player presses the "spin" button. This means theoretically, the server could see the player's bet, then generate a result based on a modified algorithm that tips in the house's favor.
Of course, most legal platforms don't do this. But the possibility exists architecturally – and that's enough to breed distrust among enlightened players.
Third-party audits: is it enough?
Platforms licensed by SZTFH must obtain third-party RNG certification. The biggest names:
BMM Testlabs – 30+ years of experience, one of the most recognized authorities, globally accredited in over 470 jurisdictions
eCOGRA – specialized in online gaming testing, particularly focused on the European market
iTech Labs – global compliance testing, especially strong in Asian and North American markets
GLI (Gaming Laboratories International) – one of the oldest and largest testing labs, operating since 1989
These labs run millions of game rounds in simulation. They perform statistical analyses – Chi-square tests, Kolmogorov-Smirnov tests, autocorrelation examinations – to ensure the RNG is truly random.
But there's an important limitation.
These audits are snapshots – they check the system at a specific point in time. They can't guarantee what happens between audits. And more importantly: they don't enable players to verify individual game rounds themselves.
It's like inspecting a restaurant kitchen once a year – but diners never see whether they actually got the food they ordered.
Modern players increasingly ask: why should I blindly trust an independent lab when technology already makes self-verification possible?
Provably Fair: the paradigm shift
Around 2013, a new approach emerged from the blockchain and cryptography world: Provably Fair gaming.
The principle is simple but revolutionary: every game round result must be mathematically verifiable by the player.
Here's how it works:
1. Commit-Reveal scheme
The casino pre-generates a server seed (the random number it chooses). But it doesn't communicate this directly to the player – instead, it sends the hash of this seed using SHA-256 algorithm.
A hash is a one-way cryptographic function – easy to generate, but practically impossible to reverse. This way, the casino proves it has already decided on the server seed, but can't change it after the player has seen the hash.
A hash looks like this: 5f3a8b2c7d9e1f4a6b8c3d5e7f9a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b. This is a 64-character hexadecimal string that the player receives before the game.
Why is this important?
If the casino changed the server seed after the game, the hash would be completely different. Since the player already saw the hash before the game, any modification would be immediately caught.
2. Player participation
The player also contributes their own seed (client seed). This can be anything – a string they choose, or an automatically generated random value. Some platforms allow players to manually enter any string, like "myLuckyDay2024" – others automatically generate a cryptographically secure random value.
3. Combining and result generation
Now that both seeds exist, the system combines them with a deterministic algorithm. The most common approach: concatenating the server seed, client seed, and a nonce value (game round number), then applying SHA-256 hash to the result.
The nonce ensures different results even with the same seeds – each game round has a unique nonce (1, 2, 3, etc.).
The algorithm is deterministic – same inputs always give the same output. This makes verification possible.
4. Verification
After the game, the casino reveals the original server seed. Now the player can:
Verify that the server seed's hash matches what they received before the game
Re-run the algorithm with the server seed + client seed + nonce combination
Check if the result matches what the casino reported
If everything matches – there's mathematical proof the game was fair. If not – the casino provably cheated.
In practice: implementation challenges
When Legjobbkaszino first attempted to implement a Provably Fair system for a huf online casino project in 2021, we ran into three critical problems:
Challenge #1: Performance
SHA-256 hashing is a CPU-intensive operation. If you need to hash in every single game round, this can cause significant server load on high-traffic platforms.
Our solution: Pre-computation and caching. We pre-generated a pool of server seed hashes – about 1,000-10,000 seeds and hashes – and reused them on rotation. When a pool runs out, a background process generates a new one.
This meant during real-time gameplay, we didn't need to hash – just a memory read, taking microseconds instead of milliseconds.
Challenge #2: User experience
80% of players don't understand cryptography. How do you present this without it being scary?
The best solution: a simple "Verify" button next to every game round, showing the seeds and verification process in a clean UI. Plus a demo video after registration explaining the concept in 90 seconds.
The truth is, 95% of players will never verify a single game round. But that 5% who do verify – and confirm everything works – start spreading the word in the community. This builds trust.
Challenge #3: Seed reuse
If you use the same server seed multiple times, players could theoretically figure out the pattern and exploit it. That's why you need to generate a new seed pair after every X game rounds.
Most platforms automatically rotate seeds after 1,000-10,000 game rounds. Players get notified that a new seed pair has been activated and see the new server seed hash.
Blockchain-based RNG: the next level
Provably Fair is great, but there's an even stronger approach: blockchain-based RNG.
The difference?
Decentralization and immutability.
In blockchain-based systems:
The server seed isn't generated on a central server, but on the blockchain
Every game round result is recorded on the blockchain – and this is immutable
Third parties can independently audit the entire history
Example: Chainlink VRF (Verifiable Random Function)
Chainlink VRF is a decentralized oracle service that generates guaranteed manipulation-free random numbers. The process works like this:
The smart contract requests a random number from the Chainlink network
Chainlink oracles generate cryptographic proof proving the random number is truly random
This proof is recorded on the blockchain – and anyone can verify it
The smart contract receives the random number and uses it in game logic
The advantage: Chainlink VRF mathematically proves the random number is truly random and unmanipulated – and anyone can verify this on the Ethereum blockchain.
The disadvantage: slower and more expensive than traditional approaches. Each VRF request costs about 0.1-0.25 LINK tokens (currently ~$1.5-4), and you need to wait 1-2 blocks for the result, which means 15-30 seconds.
This might be acceptable for poker games or lotteries, where a few seconds delay doesn't matter. But for a slot machine, where players want to see results immediately? Problematic.
API integration and game aggregators
Now that you understand RNG architecture, let's see how this fits into the broader technical stack.
A modern online casino platform typically doesn't develop its own games – instead, it uses game aggregator APIs that provide access to hundreds or thousands of games through a single integration.
Biggest aggregators in 2024:
SOFTSWISS – 36,700+ games, 250+ providers, single API integration
SoftGamings – 10,000+ games, 250+ providers, crypto-friendly solutions
NuxGame – 16,500+ games, 130+ providers, quick market entry
Hub88 – 12,000+ games, 150+ providers, excellent support
Integration happens through a REST or WebSocket API. The platform is essentially a wrapper around the game aggregator – it handles users, deposits, promotions, but the games themselves run in an iframe provided by the aggregator.
Critical architectural decisions:
1. Session management
You need to track every player session. If a player exits and returns, they should load right where they left off. This is typically solved with Redis-based session storage, where each session key gets a 1-2 hour TTL.
2. Balance management
The player's balance must be in real-time sync with the game. This happens between two separate systems:
Your database (master balance)
The game provider's temporary session balance
When a game ends, the two systems need to reconcile with each other. This is critical – if errors occur here, players could lose money or get free money.
3. Webhook handling
Game aggregators send webhooks for every significant event: bet placed, win occurred, game ended. You need to handle these webhooks reliably.
The biggest challenge: idempotency. What if you receive the same webhook twice? The system must recognize this has already been processed (usually based on transaction ID) and shouldn't deduct from the player's balance twice.
Compliance and regulatory architecture
SZTFH doesn't just require RNG certification – but a series of technical and operational requirements.
Mandatory system components in 2024:
1. KYC/AML integration
Every player must be identified before they can play or withdraw money. This typically happens through a third-party KYC provider API – like Onfido, Jumio, or Sumsub.
The process: player uploads an ID document and a selfie, the KYC service uses facial recognition to verify it's the same person in both images, uses OCR to extract data from the document, and cross-references with a government database.
The entire process takes 2-10 minutes, but in some cases manual review is needed – then players might wait 24-48 hours.
2. Player protection tools
Deposit limits, session time tracking, self-exclusion – all separate architectural components.
Deposit limit check: when a player deposits, the system queries the player's set limits (daily/weekly/monthly), compares with the amount already spent in that period, and if it would exceed the limit, rejects the transaction.
Real-time session tracking: a background process tracks how much time the player spends on the platform. If they reach 2 hours, a "reality check" popup appears showing how long they've played and how much they've lost/won.
3. Audit logging
Every transaction, gameplay, and system operation must be logged for audit purposes. SZTFH can request this data at any time.
An audit log entry contains: timestamp, event type, player ID, details, IP address, user agent, session ID. This data should never be deleted – typically archived in long-term storage like S3 Glacier for years.
Payment processing: the financial architecture
The online gambling market is expected to reach $132.9 billion by 2029. And every dollar flows through a payment gateway.
Typical payment stack:
Deposits: Credit/debit cards (Stripe, Adyen), e-wallets (Skrill, Neteller), crypto (BitPay, CoinGate)
Withdrawals: Bank transfer, e-wallets, crypto
Architectural challenges:
1. Multi-currency support
You don't just need to support HUF – but also euros, dollars, crypto. This requires a currency conversion service that updates exchange rates daily from an external API (like ExchangeRate-API or XE.com).
When a player deposits in HUF but plays a game denominated in euros, the system converts the amount in real-time. And when withdrawing, it converts back.
2. Transaction state machine
A payment moves through multiple states: pending → processing → completed/failed. This must be handled with a state machine, where every state transition is validated and logged.
For example, if a transaction is in "completed" state, it can't go to "pending" – only to "refunded". If you try to execute an invalid transition, the system throws an exception.
3. Fraud detection
Real-time anomaly detection with Machine Learning models. The system monitors: transaction amount, time of day, whether it's a new device, country risk score, number of transactions within 24 hours (velocity), average transaction size.
If the model predicts 80%+ fraud probability, the transaction is automatically blocked. Between 50-80% it goes to manual review. Below 50% it's automatically approved.
Performance optimization: scaling to millions of players
When the platform reaches critical mass, performance becomes the biggest challenge.
1. Caching strategy
Multi-layer caching: L1 memory cache (a few milliseconds), L2 Redis cache (1-5 ms), L3 database (10-100 ms).
The most frequently accessed data (player balance, active sessions, game metadata) are all cached. This way most queries never hit the database.
2. Database sharding
When one DB isn't enough, shard by player ID. For example, if you have 4 shards, then player ID modulo 4 determines which shard contains the player's data.
This means each shard only handles a quarter of the total database – making queries 4x faster.
3. Load balancing and horizontal scaling
Multiple server instances behind a load balancer. Nginx uses "least_conn" strategy – every request goes to the server with fewest active connections.
If traffic increases, you simply start new server instances and add them to the load balancer pool. If it decreases, you shut down the unnecessary ones.
Future trends: AI and ML in online gaming
The technological evolution of the online casino market doesn't stop at RNG and blockchain.
1. AI-powered personalization
Machine learning models analyze player behavior and give personalized game recommendations. If a player prefers high-volatility slots on Friday evenings, they'll see these prominently featured in the lobby on Friday evenings.
2. Predictive analytics
Predictive models forecast when a player will become inactive – and launch proactive retention campaigns. For example, if the model sees a player's activity has decreased over the past 2 weeks, it automatically sends them a personalized bonus offer.
3. VR/AR integration
WebXR-based virtual casinos where players can walk through a 3D Las Vegas lobby with a VR headset. The technology already exists – the question is just when enough players will have VR headsets to make development worthwhile.
4. Edge computing
For latency-critical games (live dealer games), computations run on edge servers closer to the player. So a Budapest player plays from a Frankfurt edge server, not a Far East data center – saving 10-20 milliseconds on every round-trip.
Conclusion: the new era of transparency
When Legjobbkaszino began analyzing online casino platform technical architectures in 2019, traditional RNG was the standard. Players blindly trusted, casinos operated black boxes, and independent auditors checked semi-annually.
Now, in 2026, things are different.
Provably Fair technology proved there's a better method. Blockchain-based RNG went one step further. And players increasingly reject the "trust us" narrative.
If you're building an online casino platform today, you need to make three critical architectural decisions:
1. Which RNG model do you use?
Traditional PRNG + independent audit is sufficient for SZTFH compliance. But if you want to differentiate and attract tech-savvy players, Provably Fair is the new minimum. And if you're really looking ahead, blockchain-based RNG is the investment – even if it's more expensive today.
2. How do we integrate game aggregators?
Single API for all providers (SOFTSWISS, SoftGamings, NuxGame) or multiple direct integrations? The first is faster and simpler – one integration, 10,000+ games. The second is more flexible but requires 10x more work.
Most new platforms choose the single API route, then later, as they grow, add direct integrations for strategic providers.
3. How do we scale?
Microservices architecture + Redis caching + database sharding + horizontal scaling. There's no other way if you want to serve millions of players.
But don't start with this. Start with a simple monolith that can quickly get to market. When you've reached your first 10,000 active players, then start migrating to microservices – not before.
The technology is here. Regulation is slowly catching up. Players already expect it.
The question isn't if transparency will become the new standard – but when and who will be the first to profit from it.
Which side are you on?
About the author
Tibor Tolnai is Editor-in-Chief at Legjobbkaszino, where he has been analyzing and testing online gambling platform technological architectures for Hungarian players for the past six years. Before joining Legjobbkaszino, Tibor worked as a senior backend developer at a fintech startup, where he built microservice-based payment systems processing millions of transactions daily. His technical writing has appeared on DZone, InfoQ, and other leading developer platforms. You can connect with him on LinkedIn or read more at legjobbkaszino.org.
