Ethereum: How can a deterministic wallet have one private key but multiple public keys
The Paradox of Deterministic Wallets: Why One Private Key Can’t Be Both Public and Private
When it comes to cryptocurrencies like Bitcoin, Ethereum, or others, users often rely on wallets that generate multiple private keys. This may seem counterintuitive when you consider the concept of a “private key” as a single, unique identifier for a person’s digital identity. However, there are compelling reasons why a deterministic wallet might require more than one public key.
In this article, we’ll delve into the world of cryptocurrencies and explore how deterministic wallets handle multiple private keys relative to their public addresses.
Deterministic Wallets: What Are They
A deterministic wallet is a type of digital storage that allows users to store and manage their cryptocurrency assets. Unlike non-deterministic wallets, which use cryptographically secure pseudo-random functions (CSPRF) to generate unique cryptographic keys for each transaction, deterministic wallets rely on a fixed set of private keys tied to specific public addresses.
Example: Bread Wallet
We can look at the Bread Wallet example as an illustration. Once you download and install Bread Wallet, it generates a mnemonic phrase that serves as your private key. This phrase is used to derive multiple public keys for different use cases, such as transferring funds between accounts or claiming rewards on different blockchain platforms.
The public address associated with your mnemonic phrase can change constantly, reflecting the dynamic nature of the cryptocurrency ecosystem. You may find yourself using one public address for a specific transaction, and another for a different purpose later.
Why Are Multiple Public Keys Necessary
So why do deterministic wallets need multiple public keys? The answer lies in the concept of “public addresses” and their relationship to private keys.
A public address is a unique identifier that associates a cryptocurrency with a specific user’s digital identity. In other words, it’s a kind of digital label or email address. When you generate a new public address using your mnemonic phrase, it gets associated with your wallet’s identity and allows you to receive funds from others on the blockchain.
However, the process of generating a new public address is not deterministic; it involves cryptographic calculations that take into account the entire hierarchy of private keys. To change your public address, you have to re-derive new private keys for each corresponding public address, which can be time-consuming and require multiple iterations.
Why Do You Need More Than One Private Key
So how does a deterministic wallet handle multiple private keys with respect to their public addresses? The answer lies in the way wallets store and manage private keys. When you create a new public address, your wallet generates a new pair of private keys: one for the original mnemonic phrase (the “old” key) and one for the newly generated public address.
This ensures that there are always multiple pairs of private keys associated with each public address, even if only one is used in a given transaction. This way, when you change your public address, you can simply regenerate new private keys for each corresponding old and new key, without losing any data or compromising the security of your wallet.
Conclusion
In summary, deterministic wallets require multiple private keys to manage their public addresses due to the dynamic nature of the cryptocurrency ecosystem. By generating a new pair of private keys for each public address associated with your mnemonic phrase, wallets ensure that there are always multiple pairs of private keys available, even if only one is used in a given transaction.