What is an XPUB?

(extended public key)

An xpub (extended public key) is a cryptographic key derived from a hierarchical deterministic (HD) wallet's master public key. HD wallets are a type of cryptocurrency wallet that use a specific algorithm to generate a hierarchical structure of public and private keys. This structure allows the creation of multiple key pairs (public and private keys) from a single master key.

The xpub is a key that allows the generation of child public keys, which in turn can be used to generate corresponding addresses for receiving cryptocurrency. Importantly, the xpub does not reveal any information about the private keys or the ability to spend funds. It only exposes the ability to generate new public keys and addresses within the derived hierarchy.

Sharing an xpub is considered safe for several reasons:

Privacy: Since the xpub only reveals public key information, it doesn't compromise the security of the wallet or the private keys associated with it. It allows others to view incoming transactions to the addresses generated from the xpub, but it does not provide any insight into the private keys necessary for spending those funds.

Address Generation: The xpub is used to generate the addresses that can be shared with others for receiving funds. These addresses are specifically designed to be used for receiving transactions, and revealing them does not enable anyone to access the private keys needed to move the funds.

Security: By sharing the xpub instead of individual public addresses, users can avoid the risk of accidentally reusing addresses or having to manage a long list of addresses. This can enhance security by preventing potential exposure of multiple addresses.

It's important to note that while sharing an xpub is generally safe, it's still essential to be cautious about the information you share online or with others. Even though an xpub doesn't directly expose private keys, it can still provide some information about your wallet and transaction history. Always follow best practices for online privacy and security, and consider the context in which you're sharing this information.

Where do I get an XPUB from?

Install a HD Wallet. Suitable for Bitcoin Cash (BCH) is for example Electron Cash. Suitable for Bitcoin (BTC) is for example Electrum.

Both applications can be run under Windows, Mac, Linux and Android. (Electron-Cash is also available in the Appstore for mobile Apple devices)