Block Confirmation: Everything to Know

By  Beluga Research August 30, 2023

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  • Cryptocurrency block confirmation is the process of validating and adding a block of transactions to the blockchain, ensuring immutability
  • Block confirmation is a crucial aspect of blockchain technology, ensuring the validity and immutability of transactions
  • Confirmation is achieved through consensus mechanisms like proof-of-work (PoW) and proof-of-stake (PoS)
  • The level of confirmation is determined by the number of subsequent blocks added to the blockchain, with more confirmations leading to increased security and immutability


Cryptocurrency block confirmation is the process of validating and adding a block of transactions to the blockchain, ensuring immutability. This process ensures that transactions are legitimate and secure. Proof-of-work (PoW) and proof-of-stake (PoS) are two popular consensus mechanisms used to achieve confirmation. The more confirmations a transaction has, the harder it is to change, providing higher security.

A Brief History

To understand block confirmation, it is important to take a brief look at the historical context. Blockchains were first introduced with the advent of Bitcoin in 2009. Bitcoin, as the pioneering cryptocurrency, also introduced the concept of the PoW consensus mechanism to confirm blocks.

With PoW, "miners" compete to solve complex mathematical puzzles, and the first miner to find a solution is rewarded with newly minted coins. This process, known as "mining," not only secures the network but also validates transactions within a block. Once a block is mined and added to the blockchain, it is considered confirmed.

Block Confirmation: Everything to Know

Block confirmation is crucial for maintaining the integrity and immutability of a blockchain. When a new transaction is initiated, it is included in a block and broadcast to the network. Miners then race to validate and add this block to the blockchain.

The mining process involves solving a cryptographic puzzle by repeatedly hashing the block's data until a solution is found. The solution, also known as the PoW, is a unique value that satisfies certain criteria, such as a specific number of leading zeros in the hash.

Once a miner discovers the PoW, they broadcast the solution to the network, along with the new block. Other nodes in the network then verify the validity of the block and associated transactions. If the block passes the validation process, it is added to the blockchain, becoming a confirmed block.

The level of confirmation refers to the number of subsequent blocks added to the blockchain after a specific block. In Bitcoin, for instance, a transaction is considered confirmed after six subsequent blocks have been added on top of it. The higher the number of confirmations, the more secure and immutable the transaction becomes.

Confirmation time varies depending on the blockchain's consensus mechanism and network congestion. Bitcoin's PoW consensus can result in longer confirmation times, especially during periods of high transaction volume. In contrast, newer cryptocurrencies such as Ethereum have introduced alternative consensus mechanisms like PoS, which can offer faster confirmation times.

Getting Started

To understand block confirmation, it is essential to grasp the fundamentals of blockchain technology. A blockchain is a decentralized and distributed ledger that records all transactions across a network of computers or "nodes." Transactions are grouped into "blocks," which are then linked together using "cryptographic hashes," forming an immutable chain. Each block contains a unique identifier called a "block hash," a timestamp, and a list of verified transactions.

Unique Aspects

One of the unique aspects of block confirmation is the consensus mechanism employed by different cryptocurrencies. The most common consensus mechanism is PoW, which is used by Bitcoin and many other cryptocurrencies. In PoW, miners compete to solve a complex mathematical puzzle, and the first miner to find a solution is rewarded with newly minted coins and transaction fees. The mining process requires significant computational power and energy consumption.

Another consensus mechanism, PoS, has gained popularity as an alternative to PoW. In PoS, block validators are chosen based on the number of coins they hold and are willing to "stake" as collateral. Validators are selected to create blocks based on a deterministic algorithm, and the chances of being chosen depend on the amount of staked coins. PoS is considered more energy-efficient compared to PoW but introduces different security considerations.

Confirmation time is another important aspect of block confirmation. It refers to the time taken for a transaction to be included in a block and subsequently confirmed. The confirmation time varies depending on factors such as network congestion, block size and the consensus mechanism used. In some cases, a transaction may be confirmed within minutes, while in others, it may take longer. Cryptocurrency users often consider the confirmation time when assessing the speed and efficiency of a blockchain network.


  • Security - Block confirmation enhances the security of cryptocurrency transactions by preventing double-spending. Once a transaction is confirmed and included in a block, it becomes extremely difficult to alter or tamper with the transaction history. This immutability makes cryptocurrencies resistant to fraudulent activities.
  • Decentralization - Block confirmation is a fundamental aspect of decentralized cryptocurrencies. It relies on a network of nodes spread across the globe to validate and confirm transactions. This decentralized nature ensures that no single entity has control over the network, making it more resilient to censorship and single points of failure.
  • Transparency - The confirmation process in cryptocurrencies is transparent and open for anyone to inspect. Transactions are recorded on the blockchain, which can be audited by anyone. This transparency helps to build trust among participants and reduces the need for intermediaries.
  • Speed - While traditional financial systems often involve slow and cumbersome processes for confirming transactions, cryptocurrencies can offer faster confirmation times. The time it takes for a transaction to be confirmed depends on factors such as network congestion and the chosen cryptocurrency. However, in many cases, cryptocurrency transactions can be confirmed within minutes or even seconds.
  • Global Accessibility - Cryptocurrencies operate on a borderless network, allowing individuals from anywhere in the world to participate. Block confirmation enables secure and efficient cross-border transactions without the need for intermediaries or traditional banking systems. This accessibility empowers individuals who may not have access to traditional financial services.


  • Energy Consumption - Block confirmation in some cryptocurrencies, such as Bitcoin, requires a significant amount of computational power and energy. This energy consumption has raised concerns about the environmental impact of cryptocurrencies. However, it is worth noting that ongoing efforts are being made to develop more energy-efficient consensus mechanisms.
  • Scalability - As the popularity of cryptocurrencies grows, scalability becomes a challenge. Block confirmation can be time-consuming and resource-intensive, especially during periods of high transaction volume. This can result in delays and increased transaction fees. Various scaling solutions, such as "layer 2 protocols" and "sharding," are being developed to address this issue.
  • Forks and Chain Splits - Occasionally, disagreements among participants in a blockchain network can lead to "forks" and "chain splits." These events create multiple versions of the blockchain, causing confusion and potential disruptions. Forks can occur when there are differences in consensus rules or when a significant portion of the network decides to adopt a different protocol. While forks can introduce new features and innovation, they can also create uncertainty and fragmentation.
  • Learning Curve - Understanding the intricacies of block confirmation and the underlying technology can be challenging for newcomers to cryptocurrencies. The technical nature of blockchain systems requires a certain level of knowledge to fully grasp the concepts and mechanisms involved. However, educational resources, online communities and user-friendly interfaces are continuously improving to make the learning process more accessible.