Opside Network Inc., a blockchain infrastructure startup building “zero-knowledge” rollups, announced Thursday it raised $4 million in seed funding led by Web3.com Venture Capital to expand its blockchain scaling platform.

ZK rollups are a type of technology that uses what are called zero-knowledge proofs to scale up blockchain networks by bundling transactions on a second-layer blockchain without any knowledge of what’s in those transactions. They are then submitted to the primary blockchain, such as Ethereum, in bulk.

This is done because so-called top-level “Layer 1” blockchains such as Ethereum can suffer from massive downgrades when too many transactions hit them at once. That causes congestion that slows down transaction speeds and increases fees. The use of ZK rollups both lowers transaction time and reduces fees.

Opside has developed a novel ZK-rollup-as-service platform that operates across multiple layers and combines the power of both “proof of stake” validation for sequencing and “proof of work” computation for proofing rollup blocks in its chain.

Proof of stake occurs at the second layer and behaves similarly to Ethereum 2.0, where validators can “stake,” or lock up tokens, to prove that they have a stake in the Opside blockchain to earn rewards. Proof of work is where multiple miners compete to solve computational puzzles to verify blocks before they are submitted to the Opscode blockchain and this occurs at the third layer.

All the different layers are connected via bridges that allow for the transfer of assets between them with extremely low transaction fees and greatly increased speeds. For end users, this means that transactions on Ethereum and BNB Chain will reduce costs and lower latency for blockchain applications.

Developers get the benefit of the enhanced security of ZK rollups and better user experience for their distributed apps by using a scaling solution, Opside said. According to the company, operating costs of decentralized apps do not need to provide their own computing power or maintain their own networks, which can save them a great deal of money.

Opscode also provides a general-purpose ZK rollups software development kit for developers so that they can deploy applications on Opside layer 3 based on the Ethereum virtual machine.

“This funding will enable us to continue innovating and developing our platform while expanding our team and customer base,” said Nanfeng, co-founder and chief executive of Opside, said about the funding.

Zero-knowledge rollups have been explored across the blockchain industry as a scaling solution for Layer 1 blockchains such as Ethereum for the past few years. Notable examples include Offchain Labs, which launched Arbitrum Nova for decentralized apps – and was chosen by the social media website Reddit – and the Ethereum scaling solution Polygon, which uses ZK-rollups in some of its products.  Other examples include Sovereign Labs, which raised $7.4 million in January, Starknet, zkSync and Mina.

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