Services Enabled by USL

USL, as a language and virtual machine-agnostic layer (VM), supports virtually all types of heterogeneous computations across various systems and platforms while providing Correctness guarantees based on an explicitly defined Trust Base. Because of this, USL is envisioned to allow the building of new and unique applications for its settlement service. Below, we highlight four application types enabled by USL:

Rollup-in-a-box

This service enables building L2/L3 rollups and AppChains. It supports various languages and VMs for off-chain code and on-chain smart contracts. Users can build rollups using a customizable menu to select the desired combination of system features. All rollups built using this service have their transactions settled by USL transparently and uniformly.

Multi-chain bridging

This service enables rollups and applications on USL to seamlessly bridge tokens on-chain across multiple chains without reliance on any off-chain code. Each side of a bridging operation can use a different language to generate the minting or freezing transactions, while the on-chain code may be defined using another language. USL handles this heterogeneity seamlessly and invisibly to the upper layers.

Cross-chain financial applications

This service enables Decentralized finance (DeFi) applications to transition smoothly between different rollups and AppChains using USL. For instance, a cross-chain DeFi application could enable staking Ether (ETH) on one chain and using the liquid staking token as collateral to borrow USD Coin (USDC) on another chain.

This offers the advantage of better staking or borrowing rates. In this scenario, all staking and borrowing transactions are settled on USL, even though the involved chains might use different VMs and platforms for execution. Additionally, USL validates all the accumulated trust dependencies in this transaction sequence, ensuring the user is fully aware of all the trust assumptions.

Heterogeneous ZK verification

This USL service can support different types of Zero-Knowledge (ZK) rollups or ZK applications that use various ZK platforms, such as RISC-Zero, Cairo, etc. This enables users to use the ZK platform with which they are most comfortable. USL validates these transactions by verifying their ZK proofs using the appropriate ZK backend while highlighting their trust bases.