Randomness plays a far greater role in blockchain than most realize. Beyond gaming and lotteries, it’s at the heart of trustless systems: key generation, validator elections, secure smart contracts, and more. However, generating true randomness in a fully deterministic environment like blockchain is no trivial task.

Oasis Network, through its Sapphire ParaTime, is tackling this problem with a uniquely powerful solution: confidential, verifiable randomness generated onchain. This approach not only preserves decentralization, but also enhances security and fairness in Web3 applications — all without relying on external oracles or trusted parties.

🧩 What Is RNG and Why Does Blockchain Need It?

Random Number Generators (RNGs) are fundamental to cryptographic systems and secure software. In Web2, randomness helps protect secrets, encrypt data, and fuel unpredictable game logic. In blockchain, the stakes are even higher: if your randomness can be predicted or manipulated, it can undermine the entire integrity of your application.

A few examples where RNG is critical in Web3:

  • Generating private keys that are secure and non-reproducible.

  • Selecting validators or block proposers fairly without bias.

  • Random NFT trait assignment during minting.

  • Lottery and raffle systems that reward users.

  • Game mechanics where fairness is provable and tamper-proof.

Unfortunately, most traditional blockchains are not designed to produce high-quality randomness natively. They are deterministic by design — meaning any node must reach the same outcome with the same inputs. This predictability is essential for consensus but problematic for RNG.

🛡️ Sapphire ParaTime: A Verifiable, Privacy-Preserving RNG Solution

Oasis addresses this problem at the root by combining confidential smart contract execution with trusted hardware-based entropy inside its Sapphire ParaTime.

This unique combination results in:

  • Randomness generated inside TEEs (Trusted Execution Environments) — isolated hardware environments that even the node operator cannot peek into.

  • Smart contract access to a built-in RNG API — allowing randomness to be pulled directly within EVM-compatible logic.

  • Cryptographic proofs for each result — meaning anyone can verify that the randomness is legitimate and untampered, without knowing the seed or internal logic.

This is what makes RNG on Sapphire ParaTime fundamentally different. It’s not a workaround. It’s randomness designed natively for blockchain, ensuring every number is both unpredictable and auditable.

⚙️ How RNG Works on Sapphire ParaTime

The RNG system in Sapphire ParaTime is elegant yet powerful. It abstracts complexity away from the developer while ensuring security at every step.

1. Secure Entropy via TEE

Entropy — the unpredictable input needed for randomness — is generated within secure, hardware-isolated TEEs. This ensures no validator or participant can tamper with or extract the entropy, making it truly confidential.

TEEs have long been used in sensitive systems such as hardware wallets or secure enclaves in enterprise infrastructure. Sapphire ParaTime brings that same protection directly to the smart contract layer.

2. Requesting Randomness Onchain

Developers can access randomness simply by calling an API within their smart contract logic:

let rng = await oasisRNG.getRandom({ size: 32 });

This returns 32 bytes of randomness — ideal for choosing winners, generating keys, or powering randomness-dependent game mechanics. The API also supports different types of use cases, such as signing key generation.

3. Verifiability Built-In

Every call to the RNG API returns not only the random value but also a cryptographic proof. This allows third parties, auditors, or even users themselves to verify the output — adding a new layer of transparency and accountability.

Unlike centralized RNG solutions or external oracles, this mechanism ensures no single party can cheat, predict, or replay the result.

💡 Real-World Use Cases for RNG on Sapphire ParaTime

The RNG capability on Sapphire ParaTime unlocks a range of applications that require trustless randomness:

🎮 Fair Web3 Gaming

Games need fairness to gain player trust. Traditional smart contracts struggle to implement reliable randomness without exposing the system to manipulation. With Sapphire ParaTime, developers can generate server-grade randomness directly inside smart contracts — ensuring every loot drop, spin, or dice roll is both unpredictable and verifiable.

🎲 DAO Lotteries & Validator Selection

DAOs can use RNG to select random participants for rewards, committees, or governance actions — all without relying on centralized scripts or external calls. Similarly, validators or block proposers can be rotated fairly using verifiable randomness, improving decentralization and preventing bias.

🔐 Secure Key Generation

For applications that need to generate keys securely — like identity wallets, zero-knowledge systems, or confidential voting — the RNG from Sapphire ParaTime offers entropy that is unreproducible and untraceable, even by the user themselves.

let rng = await oasisRNG.getRandom({ type: 'signing_key' });

This prevents common pitfalls like weak keys or reuse, boosting the security of everything from encrypted messaging to DeFi transactions.

🚀 Why Sapphire ParaTime Is a Game Changer for RNG

The combination of confidential execution, hardware-backed entropy, and native EVM support makes Sapphire ParaTime the most advanced platform for trustless RNG today.

📌 Conclusion: RNG as the Backbone of Fair Web3

In a world where transparency is critical and trust is earned through code, randomness needs to be more than just unpredictable — it must be provably fair. Oasis, through the Sapphire ParaTime, is setting a new standard for onchain randomness that is both confidential and verifiable.

This isn’t just a tool for developers — it’s a building block for the next generation of decentralized applications that demand higher guarantees of fairness, privacy, and cryptographic integrity.

🎯 Ready to build with Oasis RNG?

🔹 Learn more about Sapphire ParaTime
🔹 Read the official RNG API docs
🔹 Start integrating Oasis RNG into your smart contract today

In Web3, randomness is power. Make it trustworthy.