Validium

Validiums are advanced scaling solutions that enhance throughput by processing transactions outside of the Ethereum Mainnet, utilizing off-chain data availability and computation. Similar to zero-knowledge rollups (ZK-rollups), validiums utilize zero-knowledge proofs to authenticate off-chain transactions on the Ethereum blockchain.

This method prevents unauthorized state changes and increases the security of a validium chain.

These proofs, known as "validity proofs," may be implemented using ZK-SNARKs (Zero-Knowledge Succinct Non-Interactive Argument of Knowledge) or ZK-STARKs (Zero-Knowledge Scalable Transparent Argument of Knowledge). Read more about Validium

The Polygon CDK validium is one of two configuration options of the Polygon CDK.

The Polygon CDK validium is essentially a zero-knowledge validium (zkValidium), leveraging the off-chain prover of Polygon zkEVM to generate zero-knowledge proofs. These proofs are then presented as validity proofs on the blockchain.

The integration of this specific prover enhances the trustlessness aspect of the Polygon CDK validium to a significant degree.

Not only does the validium mode utilize the prover, but it also incorporates all components and functionalities of the Polygon zkEVM, with the key distinction being that it does not record transaction data on Layer 1 (L1).

One of the primary benefits of the validium configuration, compared to the zkEVM rollup option, is the reduction in gas costs. This cost efficiency is achieved by storing transaction data off-chain, with only the hash of the transaction data being recorded on the Ethereum network.