> For the complete documentation index, see [llms.txt](https://docs.fiammalabs.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fiammalabs.io/our-product-suite/pragmatically-trustless-bitvm-bitcoin-bridge/introduction/hack-resistant.md).

# Hack-Resistant

While we’re still bridging assets across chains, hackers are already on the other end, siphoning off billions — silently. From [**Ronin** ](https://rekt.news/ronin-rekt)to [**Orbiter**](https://rekt.news/orbit-bridge-rekt), from [**Multichain** ](https://rekt.news/multichain-rekt2)to [**Harmony**](https://rekt.news/harmony-rekt), there’s a new high-profile bridge hack nearly every year. And they all share one terrifying truth:

> **Hackers only need a few private keys to drain everything.**

These projects had serious teams and funding. So why couldn’t they stop it? Is decentralization on blockchain really this fragile? We analyzed 5 **major bridge exploits** and identified the core vulnerability in traditional multisig systems.

### 5 Real Bridge Disasters: From Phishing to Insider Threats

1. #### **Ronin Bridge｜$625M lost（2022.3）**

* Multisig address（5-9 TSS）
* Hackers compromised 5
* Attack analysis：[Rekt - Ronin Network - REKT](https://rekt.news/ronin-rekt)

2. #### **Multichain｜130M lost（2023.7）**

* Multisig address（Parameters Unknown）
* Hackers compromised a critical number of SK shares
* Attack analysis：[Rekt - Multichain - REKT 2](https://rekt.news/multichain-rekt2)

3. #### **Harmony Horizon｜100M lost（2022.6）**

* Multisig address（2-5 TSS）
* Hackers compromised 2
* Attack analysis：[Rekt - Harmony Bridge - REKT](https://rekt.news/harmony-rekt)

4. #### Heco Bridge | 99M lost（2023.12）

* Multisig address（Parameters Unknown）
* Hackers compromised a critical number of SK shares
* Attack analysis：[Rekt - HECO Bridge, HTX - REKT](https://rekt.news/heco-htx-rekt)

5. #### Orbit Bridge | 81.5M lost （2024.1）

* Multisig address（Parameters Unknown）
* Hackers compromised a critical number of SK shares
* Attack analysis：[Rekt - Orbit Bridge - REKT](https://rekt.news/orbit-bridge-rekt)

***

What do these bridges have in common? 👉 They all used **multisig**. And while that sounds secure — it’s dangerously misleading.

So, we’ve built a **new kind of architecture that makes this entire category of exploit obsolete**. We call it:  **Isolated Safe Architecture™.**

### ISA-Based Bridge

What Is *Isolated Safe Architecture*?

> **Every user’s funds are stored in their own personal “safe”**, co-controlled by **the user + the bridge committee**.

<figure><img src="/files/kwTT58mOIxLNOvp7xQHt" alt=""><figcaption></figcaption></figure>

This means:

* Each user’s assets are **logically and cryptographically separated**
* If a hacker wants to steal User A’s BTC, they **must** compromise User A’s key
* Even if the entire committee is compromised, **your BTC stays safe**
* To steal all bridge assets, an attacker must breach **every user** + **every committee key** — a practical impossibility

That’s why we call it a *“Safe”* — because no one else can get inside **your vault**.

We realized the real fix isn’t just “harder locks. It’s making sure **there’s no single vault to drain in the first place**. Fiamma Bridge is fundamentally different from traditional multisig bridges.

> In Fiamma, **every deposit is isolated and controlled by a different set of multisig signers**.