How Are Bitcoin Transactions Conducted?

Bitcoin Transactions and Their Importance in the Decentralized Financial World

Bitcoin transactions are essentially digital messages that record the transfer of Bitcoin from one user to another. These transactions ensure transparency, security, and immutability by using blockchain technology.
The significance of Bitcoin transactions in the decentralized financial world lies in their ability to eliminate intermediaries and provide a transparent and secure solution for value transfer. In traditional financial systems, banks act as intermediaries who process and verify transactions; however, in Bitcoin, this role is performed by a network of users, or decentralized nodes. This feature makes Bitcoin transactions not only faster and more cost effective but also resistant to censorship and fraud.
Moreover, Bitcoin transactions are completely transparent. Every transaction is publicly recorded on the Bitcoin network, and anyone can view the transaction history on the blockchain. However, the identities of users behind Bitcoin addresses remain anonymous, creating a balance between transparency and privacy protection.

What is Bitcoin and How Does It Exist?

Bitcoin is a decentralized digital currency introduced in 2009 by an individual or group using the pseudonym Satoshi Nakamoto. Unlike fiat currencies such as the dollar or euro, Bitcoin has no physical form and is not controlled by any government or central authority. This digital currency operates based on blockchain technology, a public ledger that records all transactions conducted on the Bitcoin network.
Bitcoin does not physically exist; rather, it is stored as records on the blockchain. The blockchain can be likened to a massive accounting ledger that permanently and immutably records every Bitcoin transaction. Each Bitcoin is essentially a chain of digital signatures that transfers ownership from one user to another.
To hold and manage Bitcoin, users utilize digital wallets. These wallets contain two important keys:

1. Public Key

The public key, sometimes called the Bitcoin address, is a string of randomly generated numbers and letters. This key acts as a public identifier to receive Bitcoin and can be shared with others. Simply put, the public key is similar to a bank account number that people can use to send you money.
An important feature of the public key is that anyone can see it and use it to send Bitcoin, but this access does not in any way allow spending or transferring Bitcoin. This transparency, without compromising security, is one of the key advantages of Bitcoin technology.

2. Private Key

In contrast, the private key is a secret, randomly generated string of numbers and letters that must be fully protected. This key acts as a "password" that allows its owner to spend the Bitcoins associated with the related public address. The private key is mathematically linked to the public key, but it is impossible to derive the private key from the public key.
The private key is used to digitally sign transactions, and any disclosure of it can lead to the loss of Bitcoin assets. Therefore, protecting the private key is critically important. Users must ensure the secure storage of their private keys and never share them with others.
One of Bitcoin’s key features is its limited supply. Only 21 million Bitcoins can ever exist, making it a scarce asset. This feature, alongside the network’s decentralization and high security, has made Bitcoin one of the most valuable digital assets in the world.

The Stages of a Bitcoin Transaction: From Initiation to Final Confirmation

A Bitcoin transaction is a multi step process in which Bitcoin is transferred from one user to another. This process is transparent and secure, and it is verified by the Bitcoin network.

Transaction Creation

The process of transferring Bitcoin begins with creating a transaction in the digital wallet. The sending user specifies the recipient’s public address, the amount of Bitcoin to transfer, and the transaction fee. The recipient’s public address functions like a bank account number and allows the recipient to receive Bitcoin.

Digital Signature

After completing the transaction details, the sender’s wallet signs the transaction using the private key. This signature acts as proof of Bitcoin ownership by the sender and indicates that the user is authorized to spend these Bitcoins. The private key is never sent to the network, ensuring the transaction’s security.

Broadcasting to the Bitcoin Network

The signed transaction is sent to the Bitcoin network. At this stage, the transaction is broadcast and enters a temporary space called the mempool. The mempool is essentially a holding area where transactions wait for confirmation.

Confirmation by Miners

Miners, which are nodes with high processing power, select transactions from the mempool and verify them. Miners confirm the validity of the digital signature and the sender’s Bitcoin balance. They then place transactions into a new block and attempt to solve a complex mathematical problem. This process is known as Proof of Work.

Adding to the Blockchain

The miner who solves the mathematical problem first adds the new block to the blockchain. This block contains all the transactions that the miner has verified. After the new block is added to the chain, the transactions are confirmed.

Receiving Additional Confirmations

Once recorded on the blockchain, the transaction receives one confirmation. However, to ensure finality, it is common to wait for 6 confirmations (6 subsequent blocks). Each block is created approximately every 10 minutes, so this process may take 30 to 60 minutes.

Transaction Finalization

After receiving sufficient confirmations, the Bitcoin is transferred to the recipient’s address and the transaction is fully finalized. From this point onward, the transaction is immutable and cannot be reversed.
Thanks to blockchain technology and its decentralized model, Bitcoin transactions offer a transparent, secure, and fraud resistant process. These stages from transaction creation to final confirmation demonstrate the power of Bitcoin technology in creating a financial system that operates independently without relying on trust in intermediaries. These features have made Bitcoin one of the most important financial tools in the modern world.

Inputs and Outputs: How Value is Processed in Bitcoin Transactions

Bitcoin transactions are designed based on the model of Inputs and Outputs. In this model, each transaction consists of several inputs and outputs that define how value is transferred between users.

The Concept of Inputs

Inputs are the Bitcoin sources that a user utilizes to send Bitcoin. Each input refers to a previous transaction that transferred Bitcoin to the sender’s public address. These inputs indicate how much Bitcoin the user owns and can use to execute a new transaction.
For example, if you received 0.5 Bitcoin from one previous transaction and 0.3 Bitcoin from another, to send 0.7 Bitcoin you need to combine both inputs.

The Concept of Outputs

Outputs represent the destinations of the sent Bitcoins. Each transaction typically has at least one output that specifies the amount of Bitcoin sent to the recipient’s address. Additionally, there may be an extra output to return the "change" back to the sender.
For example, if you intend to send 0.7 Bitcoin and your inputs total 0.8 Bitcoin, 0.7 Bitcoin is sent to the recipient, and 0.1 Bitcoin is returned as "change" to your address.

The Role of Miners in Confirming and Recording Bitcoin Transactions

Miners are one of the key components of the Bitcoin network responsible for verifying transactions and adding them to the blockchain. This process, known as "mining," involves solving complex mathematical problems that ensure the security and integrity of the Bitcoin network.

Proof of Work Process

Miners use the Proof of Work algorithm to confirm transactions. In this process, miners must solve a mathematical puzzle that requires significant computational resources. The goal is to generate a cryptographic hash that meets specific criteria (for example, starting with a certain number of zeros).
This process not only verifies transactions but also allows the Bitcoin network to add new blocks to the blockchain. The first miner to solve the mathematical problem creates the new block and receives a reward.

Transaction Selection by Miners

Miners typically select transactions with higher fees. These fees act as incentives for miners to prioritize confirming certain transactions more quickly. For this reason, users who want their transactions to be confirmed faster usually set higher fees.

Why Can Bitcoin Transaction Confirmation Take Time?

Confirming Bitcoin transactions can be time consuming due to several factors. One of the most important is the block size limit. Each block in the Bitcoin blockchain has a limited capacity (1 megabyte) to store transactions. This limit means that only a certain number of transactions can fit into each block.
Another factor is network congestion. When a large number of transactions are sent simultaneously, a queue of unconfirmed transactions forms in the network’s memory pool (mempool).
In this situation, miners select transactions that offer higher fees since these fees serve as rewards for processing the transactions. Therefore, if your transaction fee is low, it may take a long time to be included in the next block.
Together, these factors cause transaction confirmations to take longer during peak transaction periods or times of high network congestion.

Bitcoin Transaction Fees

Bitcoin transaction fees are determined based on supply and demand within the network as well as the transaction size.
Supply and demand play a significant role in fee determination; when the number of transactions is high, competition to enter the next block increases, and users must pay higher fees to prioritize their transactions. Conversely, when the network is less congested, fees decrease.
Another factor is the transaction size, which depends on the number of inputs and outputs. For example, a transaction with multiple inputs (such as receiving Bitcoin from several different sources) occupies more space in the block and requires a higher fee.
Many digital wallets allow users to adjust the fee. If you are not in a hurry, you can choose a lower fee, and your transaction will be processed when the network is less busy. On the other hand, if you need fast confirmation, you can offer a higher fee so that miners prioritize your transaction.

The Technology Behind Bitcoin Transactions: Cryptographic Hashes and Nonces

Bitcoin uses cryptographic hashes and nonces to ensure the security and integrity of transactions.
Cryptographic hashes are mathematical functions that convert data into a fixed length string. Even the smallest change in the input data produces a completely different hash. This property enables any unauthorized modification in transactions to be quickly detected.
A nonce is a random number that miners use to find a valid hash. The mining process involves trying different nonce values until the generated hash meets specific criteria (for example, starting with a certain number of zeros). This process, called Proof of Work, ensures that adding each block to the chain requires significant computational effort.

The Unspent Transaction Output (UTXO) Model and Its Role in Bitcoin Transactions

The UTXO (Unspent Transaction Output) model is one of the key principles in the operation of Bitcoin transactions. Unlike banking systems where balances are stored centrally as account holdings, in Bitcoin, the balance of each address is defined based on a set of unspent outputs.
Each transaction on the Bitcoin blockchain consists of inputs and outputs. Inputs are spent UTXOs from previous transactions, and outputs represent new amounts that are stored as UTXOs for future transactions.
For example, if an address has received 3 Bitcoins from two previous transactions (one with 2 Bitcoins and another with 1 Bitcoin), these two amounts are maintained as two separate UTXOs.
To send 2.5 Bitcoins, all UTXOs are converted to inputs, and a new transaction is created with two outputs: 2.5 Bitcoins to the recipient and 0.5 Bitcoins as "change" back to the sender.
The UTXO model enhances security and transparency in the Bitcoin blockchain because each output can only be spent once, effectively eliminating the risk of double spending.

Current Challenges in Bitcoin Transaction Speed and Scalability

Bitcoin faces scalability challenges due to its technical limitations. The Bitcoin network can process only about 7 transactions per second, whereas systems like Visa can handle thousands of transactions per second. This limitation primarily stems from the block size (1 megabyte) and the average 10 minute interval required to create each block.
Additionally, network congestion during peak usage times causes transactions to queue, resulting in longer confirmation times. This issue also drives up fees, as users must pay higher fees to prioritize their transactions.
Compared to traditional payment systems, these limitations make Bitcoin challenging for high volume, everyday transactions and highlight the need for scalability solutions.

Lightning Network: A Solution to Increase Bitcoin Transaction Speed

The Lightning Network is designed as a layer two solution to overcome Bitcoin’s scalability issues. This technology creates payment channels off the main blockchain, allowing users to conduct transactions without the need for immediate recording on the blockchain.
Imagine Ali and Hadi want to perform multiple transactions. They open a payment channel and lock an initial amount in a joint transaction. Then, each new transaction between them is recorded off chain, and only when the channel closes is the final state added to the blockchain.
The advantages of the Lightning Network include:

• High speed: Transactions are executed instantly.
• Lower fees: Due to fewer on chain transactions, fees are minimized.
• Better scalability: A large volume of transactions can be processed without occupying space on the main blockchain.

How Is the Security of Bitcoin Transactions Ensured?

Bitcoin’s security is based on a set of cryptographic mechanisms and blockchain structure, some of the most important of which are:

1. Public and Private Key Cryptography: Every Bitcoin transaction is signed with a private key and verified with a public key. This mechanism ensures that only the owner of the private key can spend the Bitcoins.
2. Blockchain: The blockchain acts as a distributed ledger that publicly and immutably records all transactions. Each block contains the hash of the previous block, and this chained structure makes any alteration in a block require changing all subsequent blocks, which is practically impossible.
3. Collective Verification: The Bitcoin network consists of thousands of nodes that independently verify transactions and blocks. This decentralized system prevents attacks such as double spending.
4. Proof of Work: To add a new block, miners must solve a complex problem requiring significant computational power. This process ensures that only valid transactions are added to the blockchain.

Comparison of Bitcoin Transactions with Traditional Financial Systems

Is Bitcoin Suitable for Everyday Payments?

Despite its numerous advantages, Bitcoin still faces significant obstacles in being used for everyday payments.
Transaction Speed: Bitcoin transaction confirmations usually take about 10 minutes and can take even longer during periods of network congestion. This delay is not suitable for instant payments in stores.
Fees: Under normal conditions, transaction fees are relatively low, but during times of high network congestion, fees increase significantly, making the use of Bitcoin for small payments potentially uneconomical.
Price Volatility: Bitcoin’s value is highly volatile, which reduces the confidence of sellers and buyers in using it as a payment method.
Limited Acceptance: Many businesses still do not accept Bitcoin, which limits its usability for everyday payments.
However, technologies like the Lightning Network have been designed to address these issues. This network enables fast and low cost transactions, potentially making Bitcoin more suitable for small and everyday payments.

The Role of Digital Wallets in Managing and Executing Bitcoin Transactions

Digital wallets are vital tools for managing and executing Bitcoin transactions. Unlike bank accounts, these wallets do not store Bitcoin directly; instead, they manage the private and public key information necessary to access the Bitcoin stored on the blockchain.

Types of Bitcoin Wallets

1. Hot Wallets: These wallets are connected to the internet and are suitable for daily transactions. Mobile apps, desktop applications, and online wallets fall into this category. Examples include Coinbase Wallet and Electrum.

Advantages:Easy access and high speed for transactions.
Disadvantages:More vulnerable to cyber attacks due to internet connectivity.

1. Cold Wallets: These wallets are not connected to the internet and are suitable for long term and secure Bitcoin storage. Examples include hardware wallets like Ledger and Trezor, as well as paper wallets.

Advantages:High security and immunity to online hacks.
Disadvantages:More complex access and usage, especially for beginners.

How to Use Wallets

To send Bitcoin, the user needs the recipient’s address, the desired amount of Bitcoin, and to set the transaction fee. The wallet signs the transaction using the private key and sends it to the blockchain network. To receive Bitcoin, the user simply provides their public address to the sender.
Besides managing transactions, wallets play an important role in user security. Features such as encryption, two factor authentication, and private key backups help users protect their assets.

The Future of Bitcoin Transactions: Innovations and Challenges

Bitcoin continues to evolve, and upcoming innovations and challenges will play a key role in shaping the future of its transactions.

Future Innovations

Scalability Improvements:Solutions such as the Lightning Network and on chain rollups enable users to conduct faster and lower cost transactions. These technologies help reduce the load on the main network.
Development of Smart Wallets:New wallets are emerging that use artificial intelligence to enhance user experience, optimize fee settings, and increase security.
Integration with Traditional Payment Systems:Efforts are underway to facilitate the integration of Bitcoin with banking payment systems and credit cards, making Bitcoin easier for users to adopt.
Advancements in Privacy:Technologies like Taproot and Schnorr Signatures improve the security and privacy of transactions.

Future Challenges

Widespread Adoption:For Bitcoin to be accepted as a primary payment method, more merchants and businesses need to embrace it. This requires cultural and infrastructural changes.
Price Volatility:Bitcoin’s value is highly volatile, which poses a significant barrier to everyday use. The development of Bitcoin linked stablecoins can partially alleviate this issue.
Scalability Issues:As the number of users increases, the Bitcoin network requires further improvements in transaction processing capacity to compete with traditional financial systems.
Environmental Impact:The high energy consumption involved in Bitcoin mining remains a major concern. Transitioning to eco friendly models such as Proof of Stake could be a viable solution.