What are Ledger Applications and Why do I Need Them?

Ledger hardware wallets use applications to manage your cryptocurrencies. These can be installed onto your device through Ledger Live’s Manager. But why do we use apps for the Ledger Nano X and Ledger Nano S? What is their purpose? Let’s take a closer look.

Applications on Ledger devices play a vital role in managing your crypto assets – for each cryptocurrency, there’s a dedicated app. These apps can be installed onto your hardware wallet by connecting it to Ledger Live.

So what do these apps do? To summarize it shortly, the app on your hardware wallet calculates private keys based on your 24-word recovery phrase and are used to verify receiving addresses and transactions. While we want to give you some more insight into this process, we also want to explain a bit more as to why we use an application-based system.

The creation of your private keys

Your 24-word recovery phrase is a backup of all your crypto assets – which must be stored securely. Each individual cryptocurrency address is managed by a Private Key. While the 24 words can grant access to all your crypto accounts, each Private Key only does so for one specific crypto asset address.

Designed for optimal security, your apps do not have access to the recovery phrase. Instead, it sends a request to calculate the Private Keys from your 24 words, based on a specific parameter called a derivation path. The derivation path is unique for each crypto asset. After having satisfied necessary security checks, the app will receive a reply with the Private Keys. All of this takes place in the Secure Element chip of course, to make sure that these sensitive operations remain secure.

Great! You now have the Private Keys of your desired cryptocurrency on your hardware wallet! The application can then derive your Public Keys from it. These are also better known as your addresses. This is where anyone can send cryptocurrencies to you.

We’ve made the following diagram to summarize this process:

So why do I still need my applications after this?

Your Private Keys are still very important afterwards – they are needed for verifying your receiving address and transactions. Without using your private keys, you cannot perform either of these actions. Let’s take a look at how this works:

1. You’re trying to make a Bitcoin transaction, for which you need your Bitcoin Private Key to sign (i.e. give the approval for) the transaction. After determining how much Bitcoin you want to send to a certain address, your wallet application will send a signature request to your Ledger hardware wallet.
   
2. Your Ledger device will then show you what exact request was made by the wallet application on its screen so that you can verify if it indeed matches the transaction you’ve set up. This mitigates a so-called man-in-the-middle attack.
   
3. After having verified and approved the transaction, the application on your Ledger device will create the correct signature by using the Private Keys and send this back to the wallet application.
   
4. After this, the wallet application will broadcast the transaction to the blockchain – your transaction is completed!

但应用程序之间不能交互吗？

不能交互。 Ledger 决定为每种加密货币使用单独的应用程序。 此举是出于安全考量，同时也允许第三方参与开发（稍后会详细介绍）。

从安全上讲，是为了确保在某个加密货币应用程序出现问题时，任何其他加密资产都不会受其影响。 此原则由 Ledger 设计开发的 BOLOS 定制操作系统强制执行。

Ledger 不仅是唯一创建了自有操作系统的硬件钱包提供商，也同样是少数使用应用程序系统的提供商之一。 其他硬件钱包使用所谓的单片固件。 在此类钱包中，如果一种加密货币的代码出现问题，就可能会影响所有其他加密货币。

第三方开发

由于应用程序彼此独立且无法交互，因此我们可以允许 Ledger 外部人员自行开发应用程序。 我们已经能够发布 40 余种由加密货币社区成员和开发人员创建的程序 – 在此表示非常感谢！

当然，我们仍然会进行审核，确保这些程序满足最高的用户体验与安全标准。 You can read more about the process of submitting an application to us here.

如果卸载应用程序，我的加密货币会消失吗？

不用担心，您仍然可以访问自己的加密货币！ 如本文开头所述，您的 Ledger 设备根据名为衍生路径的特定参数，从 24 词恢复短语计算出您的私钥。

也就是说，如果您设备上的恢复短语始终相同，那么其计算结果也将保持一致。 因此，再次安装该应用程序时，就可以访问与此前相同的地址。

不断学习！ 如果您喜欢学习加密货币和区块链的知识，请观看我们的“区块学校”视频。 如何保证加密货币安全。