Bitcoin: Is there really such a thing as a “Bitcoin address”? Since all I need to spend a UTXO is to provide a scriptSig

Understanding the Structure of Bitcoin Transactions: The ScriptSig

When it comes to sending cryptocurrency transactions on the Bitcoin network, many users wonder what exactly is needed to spend their coins. A common question lies at the heart of the matter: what is the “Bitcoin address” and how is it obtained or used?

To answer this question, let’s take a closer look at the fundamental components of a Bitcoin transaction.

The ScriptSig

A script signature is the key component that allows you to send funds on the Bitcoin network. It is essentially a way to authorize the transfer of coins from your wallet to another party (the recipient). The script signature is made up of three parts:

• ScriptSig

  

  : This is a public key that is used to sign transactions.

• PubKey

  (or ScriptPubKey): This is the private key associated with the script signature and is usually stored in your wallet.

• Unlock Script (or LockScript) – This script is used to unlock a specific amount of coins and specify how it should be spent.

Essentially, when you want to spend a UTXO (Unspent Transaction Output), all you need to do is provide the scriptSig (or input script) of your wallet. The recipient only needs to know your public key (scriptPubKey) and the amount you want to receive.

The ScriptPubKey – More Than a Public Key

While it is true that the script’s public key can be thought of as “just a public key”, it actually represents a private key in Bitcoin terminology. It is used to verify the authenticity of the transaction and ensure that it is valid. The script’s public key contains all the information needed to spend a UTXO, including the amount, the recipient’s public key, and any additional parameters required by the specific transaction.

Conclusion

In conclusion, when sending funds on the Bitcoin network, you do not need a Bitcoin address or any other special permissions. All you need is your wallet’s private key (scriptpubkey) and the script signature of the UTXO you want to spend. This simplified approach has made Bitcoin transactions more accessible and convenient for users around the world.

Bitcoiners often joke that you only need three things to send cryptocurrency: a wallet, a computer, and an internet connection. But in reality, it’s much simpler than that: just your wallet and your understanding of the underlying Bitcoin protocol.