Protocol Overview

Analog aims to create a Decentralized Liquidity Network that securely connects various blockchain networks. It utilizes a central, custom-built blockchain called the Timechain to facilitate communication between different chains, thereby making the process more secure and streamlined.

The Timechain: Analog's Core

The Timechain, also known as the "Accountability Layer," is the foundation of Analog's architecture. Built using the Substrate SDK, it acts as the central record for all network activities, ensuring that cross-chain messages are processed securely.

Key Features of the Timechain:

Substrate-Based: The Timechain is built on the Substrate SDK, which enables a flexible design, forkless upgrades, fast transaction processing, and robust security.
Nominated Proof-of-Stake (NPoS) Consensus: Time Nodes secure the Timechain by validating and adding new blocks to the network, ensuring its integrity and decentralized nature.
Centralized Coordination (Hub-and-Spoke Model): The Timechain is the "hub" through which all messages and data between connected blockchains ("spokes") are routed. This design simplifies integration, streamlines communication, and enhances security by providing a single, trusted point of coordination.
Accountability Layer: The Timechain keeps a complete record of all cross-chain operations, validator registrations, network shard statuses, and governance decisions. This provides transparency and a verifiable history of all network activities.

Although the Timechain is built on Substrate SDK and leverages some of the platform’s features, including forkless upgrades, fast block times, and security-focused development, it remains an independent blockchain. For more details about the Timechain and its architectural components, check out the Timepaper .

Chronicle Nodes and Shards: Enabling Cross-Chain Communication

To manage the complexity and scale of cross-chain communication, the Timechain leverages Chronicle Nodes and a sharded network structure.

Chronicle Nodes:

These nodes are responsible for facilitating cross-chain communication by performing two main services:

Attestation Service: Chronicle Nodes monitor, validate, and post inbound cross-chain requests from external blockchains to the Timechain.
Relaying Service: They relay verified cross-chain messages from the Timechain to their destination chains for execution.

Each Chronicle Node has a Connector instance that acts as an interface with specific external blockchains, allowing them to participate in Multi-Party Computation (MPC) processes.

Shards:

To improve scalability and efficiency, the Analog network is divided into shards, which are subnetworks or clusters of Chronicle Nodes that collectively manage cryptographic operations.

Task Distribution: Shards enable the network to distribute tasks among smaller groups of Chronicle Nodes, allowing for parallel processing of cross-chain requests.
Specialized Functions: Different shards can be assigned specific roles or types of tasks, such as handling communication with a particular blockchain or a specific type of message.
Improved Throughput: By dividing the workload, shards significantly increase the network's overall transaction processing capacity, allowing for higher volumes of cross-chain messages.
Enhanced Security (Threshold Cryptography): Shards use Multi-Party Computation (MPC), specifically Threshold Signature Schemes (TSS). This means that a minimum number of members within a shard must collaborate to perform actions like signing a cross-chain message. This threshold security mechanism enhances fault tolerance and prevents single points of failure. The TSS keys are aggregate keys distributed among these permissionless shards, which then control gateway smart contracts on the connected blockchains.

Gateway Smart Contracts

External blockchains interact with the Timechain and participate in Analog's decentralized liquidity network by deploying Gateway Smart Contracts. These smart contracts act as the on-chain interface between the external chain and the Timechain's Chronicle Nodes.

Message Submission: Applications on external chains send cross-chain messages or token transfers to their local Analog Gateway contract.
Message Reception & Dispatch: The Analog Gateway contract on the destination chain receives verified messages from the Timechain and dispatches them to the target smart contract or address on that chain.
Security Integration: The Gateway contracts are designed to work seamlessly with the TSS-secured operations managed by the Chronicle Nodes and the Timechain.

Timechain EVM: Enabling Solidity Smart Contracts

To further enhance interoperability, Analog integrates Timechain EVM, an embedded EVM execution environment directly within the Timechain runtime. This allows developers to use familiar Ethereum tools and write smart contracts in Solidity.

Timechain EVM uses two key technologies:

PolkaVM: A lightweight, high-performance VM optimized for Substrate-based blockchains. PolkaVM compiles smart contracts (including Solidity) into optimized machine code, leading to faster execution and lower transaction fees.
pallet-revive: A Substrate module that provides the embedded EVM execution environment within the Timechain runtime. pallet-revive allows the Timechain to natively process and execute PolkaVM-compiled smart contracts, acting as a bridge between Ethereum-like transactions and the Timechain's runtime.

Check out Timechain EVM for more details.