What is a Blockchain Address?

By Julia Cook
Published Jun 14, 2022 and updated Mar 20th, 2023

A blockchain address, or ‘crypto address,’ is something like a cryptographic email address that is unique to the address holder.

A blockchain address is a personal address that is unique to the holder. Like an email address it only provides location data, but not access to the content of the address location. So, just as when someone sends you an email, they can only send the email to you, but do not have access to your email account, so too when a person uses the address to send data to a recipient, they do not have access to the recipient’s data, including the data or coins that they just sent.

The address is type of public key that is a hash composed of a long sequence of letters, numbers and functions that make it difficult to guess. It only has a once-off use which is to act as a link between the public and private data of a particular user. This pairing between the public and private domains is known as an ‘asymmetric key pair.’ The key is created by a private key holder (such as someone who holds some kind of wallet) to perform a specific function such as to verify the contents of a wallet or to sign transactions, thereby allowing the coins or other data to be transferred to or from the account. The other user will also need to have access to the key and approve of its use in order for it to perform its function.

The fact that addresses are located on the public blockchain means that all of the blockchain’s users are able to see all of the transactions that take place, such as the transfer of Bitcoin (BTC) between accounts. However, as e-wallet addresses are presented as a string of code, no-one knows who the owners of either part of the exchange are being transferred between.