Cut-through: Everything to Know

By  Beluga Research August 2, 2023

Image for Cut-through: Everything to Know


  • Cut-through is a technique used in cryptocurrencies to optimize the storage and processing of transactions on blockchain networks
  • It involves removing unnecessary data from transactions and consolidating them to reduce the overall size of the blockchain, improving efficiency and scalability
  • Cut-through works by identifying and pruning spent transaction outputs (UTXOs) from the blockchain, thereby reducing blockchain bloat
  • However, there are also potential disadvantages, such as centralization concerns, security vulnerabilities and trade-offs in privacy


Cut-through is a technique used in cryptocurrencies to optimize the storage and processing of transactions on blockchain networks. Cryptocurrencies operate on decentralized networks known as blockchains, which are essentially distributed ledgers that record all transactions. Each transaction is bundled into a block and added to the chain in a sequential manner. However, as the popularity of cryptocurrencies has grown, so has the number of transactions being conducted on these networks. This surge in transaction volume has led to scalability challenges, particularly in terms of processing speed.

A Brief History

To better understand the concept of cut-through, it is helpful to explore the historical context in which it emerged. Bitcoin, the first and most well-known cryptocurrency, was introduced in 2009 by an anonymous individual or group known as Satoshi Nakamoto. In the early years, Bitcoin transactions were processed relatively quickly due to the low number of participants in the network.

As Bitcoin gained traction and more users started transacting, the limitations of its original design became apparent. The blockchain's limited block size and the time it took to validate transactions resulted in delays and increased fees. This scalability issue prompted the development of various solutions, including the concept of cut-through.

Cut-through: Everything to Know

Cut-through is a technique that aims to optimize the storage and processing of transactions within a blockchain network. It involves removing unnecessary data from transactions and consolidating them to improve efficiency. By eliminating redundant information, cut-through reduces the overall size of the blockchain, making it more manageable and scalable.

In traditional blockchain architectures, each transaction contains inputs and outputs. Inputs refer to the funds being spent, while outputs represent the destination addresses and the corresponding amounts. With cut-through, instead of storing every input and output separately, the network consolidates similar or redundant information, resulting in a smaller transaction size.

This consolidation is achieved through the use of cryptographic techniques, such as Merkle trees. Merkle trees allow for the creation of a single hash that represents a set of transactions. This hash is then stored on the blockchain, while the original transactions can be pruned or removed. The hash serves as a proof of the transaction's validity, ensuring that it cannot be tampered with.

Cut-through offers several benefits to blockchain networks. Firstly, it reduces the storage requirements, which is crucial for networks with limited resources. By eliminating unnecessary data, the blockchain becomes more lightweight and can be stored and replicated more easily across network nodes.

Secondly, cut-through improves transaction processing speed. With smaller transaction sizes, more transactions can fit within a single block, allowing for faster confirmation times. This is particularly important for cryptocurrencies aiming to compete with traditional payment systems, where speed is a critical factor.

Furthermore, cut-through can help alleviate scalability concerns. As more users join a blockchain network, the ability to process a higher volume of transactions becomes essential. By optimizing the storage and processing of transactions, cut-through enhances the overall scalability of the network, enabling it to handle increased transaction throughput.

Getting Started

To understand cryptocurrency cut-through, it is necessary to grasp the basic structure of a blockchain. A blockchain is a distributed ledger that records transactions across a network of computers, known as nodes. Each transaction is bundled into a block and added to the chain in a linear fashion. This ensures the immutability and transparency of the transaction history.

However, as more transactions occur, the blockchain grows in size, potentially resulting in longer confirmation times and higher storage requirements for network participants. This is where cut-through comes into play. Cut-through is a technique that aims to reduce the size of the blockchain by eliminating unnecessary data while preserving the integrity of the transaction history.

Unique Aspects

The primary mechanism behind cut-through is the identification and removal of spent transaction outputs (UTXOs) that are no longer needed for future transactions. UTXOs represent the unspent funds associated with specific addresses in a blockchain. When a transaction occurs, the UTXOs used as inputs are consumed, and new UTXOs are created as outputs. Over time, the number of UTXOs can accumulate, leading to blockchain bloat.

Cut-through addresses this issue by pruning spent UTXOs from the blockchain. Instead of storing each individual UTXO, the blockchain retains only the unspent outputs. By removing spent UTXOs, the blockchain size can be significantly reduced, resulting in faster syncing, improved transaction processing, and enhanced scalability.

The cut-through technique is implemented differently in various blockchain protocols. For instance, in Bitcoin, cut-through is achieved through a process called "coin selection." Coin selection involves identifying and combining multiple UTXOs to form a new transaction while discarding the spent ones. This consolidation reduces the number of UTXOs, thereby optimizing the blockchain size.

In addition to reducing blockchain bloat, cut-through can also have a positive impact on transaction fees. By eliminating unnecessary UTXOs, transaction sizes can be reduced, leading to lower fees. This can make cryptocurrencies more accessible and affordable for users, fostering wider adoption and utility.

Furthermore, cut-through can contribute to the overall network security and privacy. By condensing the blockchain, the storage requirements for network participants decrease, enabling more nodes to participate and strengthen the decentralization of the network. Additionally, the removal of spent UTXOs can enhance privacy by reducing the traceability of transactions, as the history of spent outputs becomes less accessible.


  • Enhanced Transaction Speed. Cryptocurrency cut-through enables faster transaction processing by optimizing the way transactions are confirmed and added to the blockchain. This allows for quicker settlement times and improves the overall user experience.
  • Improved Scalability. Efficient cut-through mechanisms can help address the scalability challenges faced by many cryptocurrencies. By streamlining the transaction confirmation process, the network can handle a larger volume of transactions without sacrificing speed or incurring high fees.
  • Lower Transaction Costs. With faster transaction confirmation and improved scalability, cryptocurrency cut-through can lead to lower transaction costs. Users can enjoy reduced fees when sending or receiving funds, making cryptocurrencies more affordable for everyday use.
  • Increased Adoption Potential. The ability to process transactions quickly and at a low cost makes cryptocurrencies more attractive to merchants and businesses. Cryptocurrency cut-through can help drive wider adoption by offering a seamless and cost-effective payment solution.
  • Network Efficiency. By optimizing transaction processing, cut-through mechanisms can improve the overall efficiency of a cryptocurrency network. This means that the network can operate smoothly even during periods of high transaction volume, without experiencing significant bottlenecks or delays.


  • Centralization Concerns. Some cut-through mechanisms may introduce centralization risks by relying on a smaller group of participants to validate and confirm transactions. This can potentially undermine the decentralized nature of cryptocurrencies and create a single point of failure.
  • Security Vulnerabilities. Implementing cut-through functionality requires careful consideration of security measures. If not properly designed and implemented, cut-through mechanisms could introduce vulnerabilities that may be exploited by malicious actors, leading to potential attacks or fraud.
  • Complexity of Implementation. Integrating efficient cut-through mechanisms into a cryptocurrency network can be a complex task. It requires careful planning, rigorous testing, and coordination among developers and stakeholders. The complexity involved may pose challenges and delays in implementing such features.
  • Potential for Forks or Incompatibilities. Introducing cut-through functionality to an existing cryptocurrency network may require a hard fork, which can result in a split in the community and the creation of multiple versions of the currency. Additionally, compatibility issues may arise when interacting with wallets or other services that do not support the new cut-through features.
  • Trade-Offs in Privacy. Certain cut-through mechanisms may impact the privacy features of a cryptocurrency. For example, techniques that aggregate transactions to improve efficiency may also make it easier to trace the flow of funds. This trade-off between efficiency and privacy needs to be carefully considered and balanced.