Meet Randcast: Architecture Design Topping Off, Alpha Version in Early 2022

ARPA Official
5 min readOct 12, 2021



The Metaverse era has come, resulting in the strengthening demand for verifiable random numbers.

Introducing Randcast, a verifiable, decentralized, low cost, high-efficiency random number generator to empower the creators of the metaverse.

Q3 2021 — Randcast Preliminary Design and background research

Q4 2021- Randcast architecture design & proof of concept

Q1-Q2 2022 — Randcast v1 grand launch

Q3 2022 — Randcast pilot program with leading NFT projects

The Metaverse Era Has Come

When the future comes, 2021 might be remembered as the first year of the Metaverse era.

Facebook, Google, Tencent, ByteDance, SONY, and HTC — among many other internet leaders, veteran digital players and shrewd investors, are taking turns to pour money into the destined-to-come Metaverse.

During the Q2 earnings call, Mark Zuckerberg outlined his vision in turning Facebook into a Metaverse company, and Facebook’s first VR conference app went viral. Tencent and ByteDance are entering the metaverse via strategic partnerships and investments. The former partners with Roblox, while the latter invested in Mycodeview / Reworld, Roblox’s competitor, and a VR start-up Pico Interactive.

It is almost certain that such a virtual universe would seed and sprout by mirroring the physical world human beings live in, where countless random events and mutations result in the emergence of our species in a mind-bending way.

That’s what we aim to provide to the future Metaverse, from the tangible world to Web 3.0 — a decentralized and open internet.

We see a strengthening demand for verifiable random numbers. Along with the popularity of decentralized games, lotteries, and NFT collectibles, while in contrast, the lack of VRF products for mass adoption is far from being appropriately addressed.

What if human beings seek to evolve from physical mortality to virtual immortality when virtuality becomes a reality? What if Metaverse’s development is truly “beyond” the existing universe within which new species originate and evolve, with mysterious random events and mutations. What if everyone can build their universe in a free, open and fair way?

Randomness shall create all the beautiful enigmas of Metaverse. We shall enable it.

Introducing Randcast, Random Metaverse Seed

Randcast, our in-development verifiable Random Number Generator (RNG), is built to catalyze such a free, open and creative Metaverse.

We had several brainstorming sessions during the ideation phase. Most of the team had decades of gaming background, and the name “Randcast” appealed to everyone as soon as it was proposed. You can cast a dice, and you can cast a spell. Why not cast the dice and use random numbers to determine the direction of the game world? The name, Randcast, represents both our identity as gamers and the application scenarios we hope this product will bring to the metaverse for players.

We agree that (leaving out physical devices), at the current stage, the major pillars of Metaverse include blockchain, game and hash power — all see randomness underlying:

For blockchain, its foundation is constituted of cryptographic features like public-private key pairs, and the digital signatures generated randomly; in games, input and output randomness make sure that players have an equal chance; while in the context of hash power, nonce (number used once) involves in validating the proof of work.

However, as Turing Award recipient Donald Ervin Knuth’s quote reads:

“Random numbers should not be generated with a method chosen at random.”

The architecture of Randcast is prudently designed with the equipment of sophisticated encryption algorithms, in which ARPA has strong confidence building on years of work in this field.

Roadmap Update

Q3 2021: Randcast Preliminary Design

During Q3, the team finalized the idea of Randcast, a verifiable RNG and part of ARPA product offerings. We first conducted extensive and in-depth background research in this direction, including current user needs, application scenarios, and possible innovations we could bring to random number use cases. For Randcast as a product, we defined its mission and expectations in this quarter and devised a professional branding scheme, including official website design. ARPA tech team finished deep dive into DFINITY, BLS threshold signature, and MEV.

Q4 2021: Randcast Architecture Design & Proof of Concept

By looking into the fundamentals of RNG, we were able to break down the design according to the major properties of verifiable randomness respectively.

The technical architecture we considered before was to build our own BLS computing network. Still, now we have turned our attention to bridge DFINITY, which can further speed up the random number generation process and reduce generation cost while still using BLS threshold signature as generators, ensuring the fairness and verifiability of random numbers. The ARPA tech team is still researching and comparing the two approaches, and Randcast technical architecture is yet to be finalized. Randcast’s official website is going live in Q4 as well. More details will be released soon.

Q1-Q2 2022: Randcast v1 deployment & Upgrades

This shall lead us into the next phase to tenon the beams and columns into a solid structural frame, on which we plan to deploy the official Randcast v1 in Q1 2022.

It shall be easy to use for developers to integrate so that they could fully devote themselves to what they do better; it shall be low-cost but high-performing, so that on-chain games, NFT collectible or lottery projects wouldn’t worry about extra fees becoming the roadblock on its way to mass adoption.

Thenceforth, Randcast will generate revenue from developers to foster the later transit into its young adulthood and further to its maturity, when it could serve essential randomness to the blockchain world and evolve abreast.

Q3 2022: Randcast Pilot Program

Aligned with our vision to enable low-cost, high-efficiency verifiable randomness for metaverse, ARPA will form a pilot program for projects and developers to utilize Randcast and raise awareness of verifiable randomness sources. We are calling developers to pursue this endeavor together.

About ARPA

ARPA is a blockchain-based solution for privacy-preserving computation, enabled by Multi-Party Computation (“MPC”). Founded in April 2018, the goal of ARPA is to separate data utility from ownership and enable data renting. ARPA’s MPC protocol creates ways for multiple entities to collaboratively analyze data and extract data synergies while keeping each party’s data input private and secure. ARPA allows secret sharing of private data, and the correctness of computation is verifiable using the information-theoretic Message Authentication Code (MAC).

Developers can build privacy-preserving dApps on blockchains compatible with ARPA. Some immediate use cases include: credit anti-fraud, secure data wallet, precision marketing, joint AI model training, key management systems, etc. For example, banks using the ARPA network can share their credit blacklist for risk management purposes without exposing their customer data or privacy.

Team members have worked at leading institutions such as Google, Amazon, Huawei, Fosun, Tsinghua University, Fidelity Investments. ARPA is currently assisting the China Academy of Information and Communications Technology in setting the national standard for secure multi-party computation. ARPA is a corporate member of MPC Alliance and IEEE and is in partnership with fortune 500 companies to implement proofs-of-concept and MPC products. In 2019, ARPA was named the Top 10 most innovative blockchain companies in China by China Enterprise News and China Software Industry Association.

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