Proof of Work: Why Can Miners Order Transactions?

The Bottom Line: PoW Is Not “Wasted Computation,” but a Consensus Mechanism for Ordering Transactions

Proof of Work (PoW) is a mechanism that makes “writing a new block” costly, verifiable, and competitive. Miners spend computing power to find a block that satisfies the required difficulty, and the network then uses accumulated work to determine the ordering of transaction history.

In other words, miners do not order transactions because of a special identity or permission. They compete for the right to record the “next block” in an open network by completing verifiable computational work.

The core value of PoW is that it makes attacking the historical record expensive. It is not about wasting electricity; it anchors the security of the blockchain ledger to an external cost in the real world.

Why Does a Blockchain Need Proof of Work?

If a blockchain were simply a shared document that anyone could write to, it would quickly run into a basic problem: who decides what gets written on the next page?

For example, Alice and Bob submit different versions of transaction history at almost the same time. Which one should the network accept? Traditional databases usually appoint an administrator, a master node, or a centralized arbitrator to make that decision. But the goal of Bitcoin/BSV is to allow participants who do not fully trust one another to reach consensus on the same ledger in an open network.

PoW’s solution is straightforward:

Anyone who wants to write the next block must first complete a computational task that is very difficult to perform but easy to verify.

The key here is asymmetry:

• Finding the answer is hard: miners must keep trying large numbers of random values.
• Verifying the answer is easy: other nodes only need to compute a hash once to determine whether the block qualifies.

This mechanism allows anyone to compete, while preventing anyone from cheaply falsifying history.

How PoW Works: An Intuitive Example

PoW can be understood as a hash-guessing game.

Suppose the network rules require miners to find a number, combine it with the block contents, and run a hash calculation so that the resulting hash begins with many zeros.

Miners cannot use a “clever formula” to calculate the answer directly. They can only try repeatedly:

Here, the nonce is the random number or counter value that miners keep adjusting. Whoever first finds a result that meets the difficulty requirement can broadcast the candidate block to the network.

Other nodes do not need to repeat all of the miner’s previous attempts. They only need to hash the block once to verify whether it satisfies the current difficulty requirement.

This is the commonly cited property of PoW: the work is hard, but checking it is easy.

Why Can Miners Order Transactions?

Miners can order transactions not because they “own the ledger,” but because they compete to package blocks through PoW.

In general, miners follow this process:

1. Collect transactions propagated across the network.
2. Check whether the transactions are valid.
3. Select the transactions to include in a block.
4. Construct a candidate block.
5. Perform PoW calculations on the candidate block.
6. After finding a valid block, broadcast it to the network.
7. Other nodes verify the block and continue mining new blocks after it.

Whoever finds a valid block first temporarily determines the on-chain order of the next batch of transactions.

It is important to note that this decision is not permanently dictated by a single miner. If two miners find different valid blocks at almost the same time, the network may experience a temporary fork. After that, the branch that gains more accumulated work is usually the one the network continues to extend.

Therefore, the basis for ordering transactions through PoW is not trust in identity, but accumulated work.

How Does PoW Improve Blockchain Security?

PoW’s security function is mainly reflected in raising the cost of tampering with history.

Suppose an attacker wants to reverse a transaction from 10 blocks ago. They cannot simply change that one transaction and be done. Once the transaction content changes, the corresponding block’s hash also changes, which affects all subsequent blocks.

The attacker must start mining again from the modified block and catch up with—or even surpass—the accumulated work that the honest network continues to produce during that time.

This means:

• The deeper a block is, the more work has accumulated after it.
• The more PoW an attacker needs to redo.
• The higher the cost of modifying history.

This is why, in PoW networks such as Bitcoin/BSV, the more confirmations a transaction has, the harder it generally is to change.

PoW from the BSV Perspective: Miner Economics and High Transaction Volume

BSV inherits Bitcoin’s PoW model while also placing clear long-term emphasis on miner economics.

In the Bitcoin system, miner revenue mainly comes from two sources: the block subsidy and transaction fees. As the block subsidy gradually declines, miner revenue needs to rely increasingly on transaction fees over the long term.

BSV’s approach is that if miner economics are to be supported while keeping per-transaction fees low, the network must be able to carry a large number of transactions. In other words, the goal is not to make every transaction expensive, but to keep each transaction low-cost while generating sustainable revenue through extremely high transaction volume.

Therefore, BSV has long emphasized the following directions:

• Large blocks;
• Low fees;
• High transaction volume;
• Enterprise and data applications;
• High-throughput node architectures such as Teranode.

From this perspective, BSV’s vision for miner economics can be summarized as: very low fees per transaction, but extremely large transaction volume.

This is a logically clear model, but one that needs real-world validation. It requires sufficient genuine transaction demand on the network, and it also requires node software and network infrastructure to handle large-scale transactions reliably.

PoW and the Energy Debate: Does the Security Cost Match the Value?

A common controversy around PoW is energy consumption.

Supporters argue that PoW uses external costs to protect the ledger, similar to how protecting financial systems, data centers, and critical infrastructure in the real world also requires ongoing costs. PoW’s energy consumption does not exist in isolation; it is part of the security model.

Critics argue that PoW consumes a significant amount of energy, and that especially when actual network usage is insufficient, the security cost may not match the social value produced.

For Bitcoin/BSV, a more pragmatic assessment is that PoW is the core of the security model, but its economic rationality depends on whether the network can generate enough real transaction demand and fee revenue. If on-chain applications, enterprise use cases, and data transactions can reach scale, the security cost of PoW is more likely to be supported by real value.

Common Misunderstandings for Beginners

Misunderstanding 1: Miners Create Transactions

Transactions are usually created by users, wallets, or applications. The main role of miners is to validate, order, and package transactions—not to create transactions out of thin air on behalf of users.

Misunderstanding 2: The Stronger PoW Is, the Faster Transactions Become

The strength of PoW mainly affects the cost of attack and the security of the chain. The transaction experience is also affected by block intervals, network propagation speed, miner policies, and the confirmation policies adopted by applications.

Therefore, security and “speed as perceived by users” are not the same concept.

Misunderstanding 3: Miners Can Freely Change Your Transactions

Miners cannot forge your signature, nor can they spend your UTXOs. What miners can do is choose whether to include a transaction, or choose which conflicting transaction enters a block when conflicting transactions exist.

This is why private keys and signature mechanisms remain the foundation of user control over assets.

Summary: PoW Uses Work to Establish Ordering Rules for an Open Network

PoW solves a fundamental problem in open networks: without a central administrator, who decides the order of transaction history?

Through a mechanism that is “expensive to compute and cheap to verify,” PoW lets miners compete for new blocks and lets the network choose ledger history based on accumulated work. As a result, transaction ordering does not depend on identity-based authorization, but on verifiable work.

In BSV, PoW remains the core of the security model. Its long-term economic model is closely linked to large blocks, low fees, high transaction volume, and enterprise-grade applications. Whether this model can fully take effect in the future depends on whether real transaction demand and infrastructure throughput capacity can continue to grow.

References

• Bitcoin Whitepaper: https://bitcoin.org/bitcoin.pdf
• BSV Blockchain Docs: https://docs.bsvblockchain.org/protocol/bsv-blockchain
• BSV Enterprise: https://bsvblockchain.org/enterprise/