Ethereum: How does a wallet get the public key from an address?

Understanding Ethereum Wallets: Unpacking the Public Key from an Address

As a new cryptocurrency enthusiast or developer, it’s essential to understand how Ethereum wallets store and manage private keys. Despite its simplicity, understanding the inner workings of Ethereum wallets is crucial for creating secure transactions and managing funds on the platform.

In this article, we’ll delve into the process of retrieving a public key from an Ethereum address. It may seem counterintuitive at first, but you’ll be surprised by how this information is actually used to facilitate transactions on the blockchain.

The Address Format

Ethereum addresses consist of three parts:

• Prefix

  

  : A 4-character string that identifies the network (e.g., “0x”, “0XB9”)

• Group: An alphanumeric string that represents a unique identifier for the wallet or account

• Hash: A 64-character hexadecimal string that serves as a checksum

Public Key Retrieval

When you create an Ethereum address, a public key is associated with it. This public key is not the same as the private key used to sign transactions.

The process of retrieving the public key from an address involves:

• Address parsing: The wallet or smart contract takes the address and parses it into its constituent parts.

• Group extraction: The wallet extracts the group part from the address, which contains the unique identifier for the account.

• Hash analysis: The wallet analyzes the hash to determine if it’s valid and related to the owner of the account.

Why Is a Public Key Needed?

While only the public key is used to sign transactions on the blockchain, the wallet still needs to know this information to:

• Store private keys securely: Even though not actually storing the private key, wallets need to keep it secure and generate new ones as needed.

• Verify account ownership: Wallets can use the public key to verify that a particular address belongs to a specific account owner.

Sample Use Cases

Suppose you have an Ethereum wallet with an address 0x1234567890abcdef. The corresponding private key is stored securely within the wallet. To retrieve the public key, you would:

• Parse the address into its parts.

• Extract the group part (e.g., “123456”).

• Analyze the hash to verify it is valid.

With this extracted public key, you can use it to sign transactions on the blockchain and interact with other wallets that support Ethereum.

Conclusion

In conclusion, while addresses are indeed just encoded, hashed public keys with a prefix, they actually store information about an account or wallet. The process of retrieving a public key from an address involves parsing the address, extracting the group part, and analyzing the hash to determine its validity. This understanding is essential for creating secure transactions on Ethereum and managing funds effectively.

By grasping this concept, you’ll be better equipped to navigate the world of Ethereum wallets and make informed decisions when interacting with the platform.