# MAP Protocol 2.0

## Overview

Protocol 2.0 introduces TSS (Threshold Signature Scheme) based cross-chain infrastructure. It enables secure asset transfers across all chains, including Bitcoin, through decentralized threshold signatures.

## How It Works

```
Source Chain              Maintainer Network           Target Chain
     │                          │                           │
     │  1. User deposits        │                           │
     │     to Vault             │                           │
     │                          │                           │
     │  2. Maintainers          │                           │
     │     observe ────────────►│                           │
     │                          │                           │
     │                    3. TSS KeySign                    │
     │                          │                           │
     │                          │  4. Signature submitted   │
     │                          ├──────────────────────────►│
     │                          │                           │
     │                          │  5. Gateway verifies      │
     │                          │     and releases assets   │
     │                          │                           │
```

### Step-by-Step Process

1. **Deposit**: User deposits assets to Vault address on source chain
2. **Observe**: Maintainers detect and confirm the deposit
3. **Sign**: Maintainers collaboratively sign withdrawal transaction via TSS
4. **Submit**: Signature is submitted to target chain
5. **Release**: Gateway contract verifies signature and releases assets

## Key Components

### TSS (Threshold Signature Scheme)

Cryptographic technology that allows multiple parties to jointly sign without any single party holding the full key.

* **2/3 Threshold**: Requires 2/3 of Maintainers to sign
* **No Single Point of Failure**: No one can sign alone
* **Single Signature Output**: Looks like a normal signature on-chain

### Vault

TSS-controlled address that holds cross-chain assets.

* Managed by Maintainer network
* No single entity controls the funds
* Supports multiple chains including Bitcoin

### Gateway

Smart contract on each chain for signature verification.

* Verifies TSS signatures
* Executes withdrawals
* Handles TSS key updates

### Maintainer

Network participant that observes events and participates in signing.

* Must be a registered Validator
* Participates in KeyGen and KeySign
* Earns rewards for participation

## Security Model

### Threshold Security

* **2/3 Byzantine Fault Tolerance**: System remains secure with up to 1/3 malicious nodes
* **Distributed Custody**: Assets are never controlled by a single entity
* **Slashing**: Malicious behavior is penalized

### Why It's Secure

* **No Private Key Exposure**: Full key never exists in one place
* **Decentralized Signing**: Multiple independent parties required
* **Economic Security**: Maintainers stake assets at risk

## Supported Chains

* **Bitcoin**: Full support via TSS Vault
* **Ethereum & EVM Chains**: Gateway contract verification
* **Solana**: secp256k1 verification via Gateway
* **Any Chain**: Can support any chain that verifies signatures

## Advantages over v1

| Aspect          | v1 (Light Client)            | v2 (TSS)                       |
| --------------- | ---------------------------- | ------------------------------ |
| Bitcoin Support | ❌                            | ✅                              |
| Gas Cost        | Higher (proof verification)  | Lower (signature verification) |
| Implementation  | Need light client per chain  | Universal TSS                  |
| Speed           | Depends on light client sync | Fast threshold signing         |

## Fusion with Light Client

Protocol v2 can integrate light client verification for enhanced security:

* TSS provides fast finality
* Light client provides additional trustless verification
* Best of both worlds

## Use Cases

* **Bitcoin Cross-chain**: Bridge BTC to EVM chains
* **Asset Transfers**: Fast and secure token transfers
* **LP-based Liquidity**: Liquidity providers earn fees
* **Multi-chain DeFi**: Access liquidity across chains

## Getting Started

* **Become Maintainer**: See [Compass-TSS Guide](/compass-tss-crossx/overview.md)
* **Provide Liquidity**: Deposit assets to Vault
* **Use Cross-chain**: Interact with Gateway contracts

## Roles in v2

| Role        | Responsibility                      | Reward           |
| ----------- | ----------------------------------- | ---------------- |
| Validator   | Block production on MAP Relay Chain | Block rewards    |
| Maintainer  | TSS signing & observation           | Cross-chain fees |
| Relayer     | Submit signatures to target chains  | Transaction fees |
| LP Provider | Provide liquidity to Vaults         | Fee sharing      |


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.mapprotocol.io/learn/architecture/v2-tss.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.