🔗Chain Abstraction

Blockchain networks operate as independent ecosystems, each with its own consensus rules, transaction validation processes, and execution environments. This fragmentation introduces interoperability challenges, requiring users and developers to navigate multiple chain-specific protocols and adapt their applications accordingly. Chain abstraction addresses this issue by creating a unified interaction layer that enables seamless asset transfers, transaction execution, and contract calls across different blockchain networks without requiring end-users to manage multiple private keys or native tokens manually. Nexchain implements chain abstraction through a combination of chain signatures and meta-transaction relayers, ensuring that users and developers can interact with decentralized applications (dApps) and smart contracts without friction.

Implementing Chain Signatures

Chain signatures provide a cryptographic mechanism that allows a single digital signature to be recognized across multiple blockchain networks. In traditional blockchain architectures, transactions are signed using chain-specific cryptographic schemes, requiring users to generate distinct signatures for each network. Nexchain employs a universal signature scheme, leveraging multi-party computation (MPC) and threshold signatures to generate a single cryptographic proof that is verifiable across different blockchains.

A chain signature is defined mathematically as follows:

H(m) represents the cryptographic hash of a transaction message 𝑚, 𝛼 is the private key component distributed across multiple parties, and 𝑝 is a large prime modulus. The use of zero-knowledge proofs (ZKPs) ensures that transactions can be validated across multiple blockchains without exposing the underlying private key. This approach enhances security while enabling seamless interoperability, reducing the need for users to manage multiple blockchain-native keypairs.

Building a Meta Transaction Relayer

A fundamental limitation of multi-chain interactions is the requirement for users to hold native tokens on each blockchain to cover transaction fees. This introduces usability barriers, as users must acquire different assets and manually approve transactions on various networks. Nexchain resolves this issue through a meta-transaction relayer, a decentralized infrastructure that enables transactions to be signed and executed without requiring users to hold native tokens.

The relayer operates by separating the transaction signer from the transaction executor. When a user initiates a transaction, a cryptographic proof of intent is generated and submitted to the relayer network. The relayer then verifies the transaction and submits it on behalf of the user, covering the gas fees in exchange for a service fee paid in Nexchain’s native token. This mechanism is governed by the following transaction flow:

First, the user signs a message containing transaction details, including target blockchain, recipient address, and execution parameters.

Second, the relayer verifies the signature using chain abstraction signatures and determines the optimal execution path.

Lastly, the transaction is submitted to the target blockchain using the relayer’s gas reserves, ensuring seamless execution without requiring user intervention.

Mathematically, the relayer follows a verification function:

where 𝑉 represents the validation function, 𝜎 is the user’s signature, 𝑚 is the transaction message, and 𝑝𝑘 is the public key associated with the user. This validation ensures that only authorized transactions are processed, preventing unauthorized transaction execution or replay attacks.

By implementing chain abstraction through universal signatures and meta-transaction relayers, Nexchain provides an efficient framework for cross-chain interactions, reducing user complexity and enhancing the scalability of decentralized applications. These advancements allow dApps to operate seamlessly across multiple blockchain ecosystems without requiring users to manually manage assets on each network, supporting Nexchain broader goal of interoperability and streamlined Web3 adoption.