비트코인은 어떻게 작동하나요?
비트코인은 인터넷 현금이라고 생각하면 됩니다. 2008년에 세상에 소개되어 몇 달 후인 2009년에 출시된 최초의 디지털 화폐입니다. 이를 이용하면 중개자 없이 다른 사람에게 직접 돈을 보낼 수 있습니다.
Bitcoin is the first virtual asset in history. It was introduced through a whitepaper in 2008 and officially launched in January 2009. The creator is known only by the pseudonym Satoshi Nakamoto.
- It operates on blockchain technology, which serves as a public ledger. Instead of banks verifying transactions, a global network of computers performs this task.
- No specific company or government owns it. It features decentralization, transparency, and open-source characteristics, serving as an alternative to the traditional financial system.
What is Bitcoin?
Think of Bitcoin as internet cash. It is the first digital currency, introduced to the world in 2008 and launched a few months later in 2009. It allows you to send money directly to others without intermediaries.
Note that we usually use the uppercase 'B' for 'Bitcoin' when referring to the network or technology, and the lowercase 'b' for 'bitcoin' when referring to the coin itself. The ticker symbol you see on exchanges is BTC.
Unlike dollars or euros in your wallet that are issued and controlled by governments, Bitcoin is decentralized. This means there is no single administrator, bank, or government running the Bitcoin network. It is a strictly P2P (peer-to-peer) system.
Why do people like Bitcoin? Because they can own and control their own money. They can send money anywhere, anytime without relying on intermediaries. Also, the system is immune to double-spending attacks, meaning one cannot attempt to use a coin in another place after spending it once.
How does Bitcoin work?
Bitcoin relies on a technology called the blockchain. You can think of the blockchain as a digital notebook that anyone can read but no one can erase.
Every transaction is recorded in a 'block' as it happens. That block connects to the previous block, forming a chain. This record is copied across thousands of computers (nodes) worldwide.
Since so many computers hold a copy of the notebook, no one can cheat. If someone tries to manipulate the ledger to give themselves more money, the other computers will reject it. Also, anyone can download Bitcoin's open-source software to participate in the ecosystem.
- Decentralization: The Bitcoin blockchain is maintained by a distributed computer network, so no central authority controls the ledger.
- Immutability: Once a transaction is added to the blockchain, it cannot be changed or deleted.
- Security: Transactions are protected by cryptographic technology, and verifying each block requires significant resources and repetitive work (solving puzzles through a process called mining).
Example of a BTC Transaction
Technically, Bitcoin does not use bank accounts with balances. Instead, it uses a system called UTXO (Unspent Transaction Output) which tracks individual digital coins in a wallet. However, to help you understand, let us look at it like a bank transfer.
Suppose Alice wants to send 1 BTC to Bob. The blockchain updates to show Alice decreasing by 1 BTC and Bob increasing by 1 BTC. This is similar to Alice writing "I gave Bob 1 bitcoin" on a public bulletin board so everyone knows the money moved.
Later, if Bob wants to send that money to Carol, the network checks the records to verify that Bob actually received the money from Alice. Because the computers constantly communicate with each other, everyone's ledger stays synchronized.
Bitcoin Mining
Mining is how the network secures itself and how new bitcoins come into existence. When you broadcast a transaction, it propagates across the network. Then, users called miners gather these transactions into a block.
To add this block to the blockchain, miners must solve a specific puzzle. The miner who solves the puzzle first adds the block and receives new bitcoins as a reward. This reward is the only way new bitcoins are created.
However, the supply is limited. Bitcoin will never exceed 21 million coins. Once all 21 million are mined (estimated around the year 2140), miners will no longer receive block rewards and will only be rewarded by transaction fees paid by users.
Proof of Work (PoW) and Energy Consumption
To maintain the security and integrity of the blockchain, Bitcoin uses a consensus mechanism called Proof of Work (PoW). This is a core part of the mining process explained earlier.
PoW is a mechanism created alongside Bitcoin to prevent double-spending in digital payment systems. Besides Bitcoin, many virtual assets use PoW to secure their blockchain networks.
The 'puzzle' miners must solve essentially refers to PoW. It is designed so that creating a block is expensive, but verifying its validity is cheap. If someone tries to cheat with an invalid block, the network rejects it immediately, and the miner cannot recover the mining cost.
PoW requires significant computing power and thus consumes a lot of electricity. This has led to debates about Bitcoin's environmental impact. However, in recent years, the mining industry has shifted significantly towards using renewable energy or wasted surplus energy.
Where is Bitcoin used?
Bitcoin is primarily used as digital currency and a store of value. You can use it like traditional currency to purchase goods online or offline. From online shopping malls to offline stores, more and more businesses are accepting Bitcoin as a payment method.
The main Bitcoin network (Layer 1) can be slow or expensive for small payments, but 'Layer 2' solutions like the Lightning Network have been developed to address these limitations.
From an investment perspective, many people buy BTC expecting its value to rise. While Bitcoin's price can be volatile, some investors view it as a way to diversify their portfolio and hedge against inflation over the long term.
Who created Bitcoin?
Bitcoin first appeared in October 2008 when Satoshi Nakamoto published a whitepaper titled "Bitcoin: A Peer-to-Peer Electronic Cash System." This paper introduced a new digital currency that operates in a decentralized system without relying on governments or banking systems.
In January 2009, the Bitcoin protocol officially started with the mining of the 'Genesis Block.' The first Bitcoin transaction took place between Satoshi Nakamoto and programmer Hal Finney. It was a transaction where Nakamoto sent 10 bitcoins to Finney.
Following the first transaction, more users found Bitcoin and began joining the network. It gained traction within small technical circles by demonstrating that this digital currency could operate without central intermediaries or authorities.
The "Bitcoin Pizza" transaction marks another significant milestone in Bitcoin's history. It was the first documented instance where Bitcoin functioned as a medium of exchange for physical goods. On May 22, 2010, a programmer named Laszlo Hanyecz purchased two pizzas for 10,000 bitcoins. This event is now celebrated annually on May 22nd as "Bitcoin Pizza Day."
Who is Satoshi Nakamoto?
The identity of Satoshi Nakamoto remains unknown. Satoshi may represent an individual or a group of developers located anywhere in the world. The name appears to be Japanese, but many believe the creator likely resides in an English-speaking country due to the high proficiency of the English used in communications. Despite numerous theories and investigations over the years, the true identity of the creator has not been confirmed.
Did Satoshi invent blockchain technology?
Bitcoin integrates several pre-existing technologies, including blockchain. The concept of immutable data structures originated in the early 1990s when Stuart Haber and W. Scott Stornetta proposed a system for timestamping digital documents.
Bitcoin also utilizes Merkle Trees, a structure developed by Ralph Merkle. Similar to modern blockchains, these early systems employed cryptographic methods to secure data and ensure integrity. However, Bitcoin represented a breakthrough because it combined these established technologies to solve the double-spending problem that hindered previous digital payment systems.
How much Bitcoin is there?
The protocol limits the maximum supply of Bitcoin to 21 million coins. As of January 2026, over 95% of this supply has been mined, yet extracting the remaining coins will take over a century. This delay is caused by the "Bitcoin halving," a recurring event that reduces the mining reward approximately every four years.
What is the Bitcoin Halving?
The Bitcoin halving is a programmed event where the block reward allotted to miners is reduced by half. The next halving is projected to occur in 2028, roughly four years after the previous event on April 19, 2024.
The halving is fundamental to Bitcoin's economic model. It ensures a steady rate of coin issuance and increases mining difficulty at a predictable pace. This controlled inflation rate distinguishes Bitcoin from traditional fiat currencies, which central banks can supply without limit.
Is Bitcoin safe?
A primary risk involving Bitcoin is the potential for hacking and theft. In phishing scams, attackers use social engineering to deceive users into revealing login credentials or private keys. If an attacker compromises a user's account or wallet, they can transfer the victim's bitcoins to their own control.
Hackers also steal Bitcoin using malware or ransomware. Malicious software can infect a computer or mobile device to gain access to a Bitcoin wallet. Ransomware attacks encrypt a user's files and demand Bitcoin payment for decryption.
Because Bitcoin transactions are irreversible and lack government backing, users must implement strict security measures to protect their assets. I recommend using strong passwords, enabling two-factor authentication (2FA), and utilizing "cold storage" or hardware wallets to keep private keys offline. It is also critical to download Bitcoin-related software exclusively from trusted sources.
Price volatility presents another risk. Bitcoin's value can shift drastically within short periods, making it a hazardous investment for those unprepared for rapid swings or losses. However, volatility has historically decreased as the asset matures and market liquidity deepens.
Conclusion
Bitcoin has evolved significantly from its inception, becoming a globally recognized asset supported by diverse use cases and growing institutional adoption. Whether for daily payments, short-term trading, long-term holding, or technical interest, Bitcoin merits further investigation.
