What is Proof of Elapsed Time (PoET) in blockchain?

Proof of Elapsed Time

The concept of Proof of Elapsed Time (PoET) can sound a bit technical even to the nuanced blockchain expert. A simple way to understand PoET is to imagine a handshake between two parties. A handshake in this example refers to a consensus or agreement. Two or more parties could either agree or disagree about something. Since all parties must be on the same page about the agreement, a blockchain system uses an intricate mechanism known as PoET.

Introduction to Proof of Elapsed Time (PoET)

Consensus mechanisms are methodologies used to reach an agreement. It’s a set of rules that helps protect networks from malicious behavior and hacking attacks. Consensus is a process by which a group of peers—or nodes or entities—on a network determine which blockchain transactions are valid and which are not. The PoET mechanism is a simple consensus mechanism that provides a fair and efficient way of determining the order of transactions in a blockchain network without using excessive computational power.

Understanding the basics of Proof of Elapsed Time (PoET)

Fundamentally, any consensus-based mechanism will involve several individual entities and a trustworthy validator. For instance, in a group discussion involving 10 students, one always finds a moderator who ensures that everyone gets ample time. Similarly, the basics of the PoET mechanism involve the validator nodes and a confidential computing processor that always upholds integrity.

How PoET works in the blockchain network

To understand the working of the PoET mechanism, let’s use an example involving 10 validator nodes in a network that wants to add a new block. Each node requests the PoET for a wait time from a trusted execution environment (TEE) to determine which node adds the next block.

TEE is the most secure area of a computing processor that offers confidentiality and integrity. The code set within the TEE assigns a random wait time to each node. The node with the shortest wait time is selected as the next block producer. For instance, let’s say node 1 has a wait time of 20 seconds, node 2 has a wait time of 25 seconds, node 3 has a wait time of 30 seconds, and so on. The node with the shortest wait time—in this case, node 1—will be selected to add the next block to the blockchain. Once node 1 has added the block, the process is repeated for the next block. We understand that the two crucial sets fundamental to the PoET mechanism are the TEE with its set of codes and the nodes communicating with the TEE.

Why PoET is important for the blockchain network

Consensus mechanisms differ in energy usage, security, and scalability, but they share one common purpose—ensuring that records are true and honest. The PoET mechanism is one of the most advanced and promises great integrity since a computerized TEE assigns wait times. This ensures that the entire blockchain functions in a secure and tamper-proof environment.

PoET algorithm

PoET is a consensus mechanism used in permissioned blockchains, which allows nodes to reach a consensus on the order of transactions in a decentralized manner. The PoET algorithm enables nodes to agree on the next node to create a block without a central authority or mining process. In the PoET mechanism, each node requests a wait time from a trusted authority (such as an oracle) and then waits for that time. The first node to complete its wait time can create the next block. This provides a way to reach a consensus on the order of transactions while minimizing energy consumption and reducing the risk of a malicious node taking control of the network.

Overview of the PoET algorithm

One can use PoET in consortium or enterprise blockchains, where the network participants are known and trusted. PoET also will come in handy when there is a need for a consensus mechanism that is efficient, secure, and scalable. One can also use it in combination with other consensus mechanisms, such as Proof of Stake or Practical Byzantine Fault Tolerance to provide additional security and resiliency.

Understanding the PoET consensus mechanism

In PoET, a validator node is selected randomly to add the next block to the blockchain. This validator is selected based on the time they have “waited” in a virtual queue. A TEE such as Intel Software Guard Extensions determines the time.

How PoET algorithm ensures fairness in the blockchain network

The PoET mechanism ensures fairness in the blockchain network. The consensus uses a random selection to determine the next block producer, ensuring that all nodes have an equal opportunity to participate. This helps create an element of fairness, but also prevents centralization and ensures that the network remains secure.

PoET use cases

Thanks to numerous benefits such as decentralization, energy efficiency, security, and scalability, enterprises trust the PoET mechanism. Sectors such as healthcare, financial services, government services, and energy management understand the benefits of blockchain with a PoET system at the center. PoET extends the benefits of a blockchain interface and makes it a valuable tool for creating secure and transparent systems in many domains.

Applications of PoET in blockchain-based systems

Most blockchain-based systems are impartial to the extent that every node or participant gets a fair chance of attempting to solve a block. With traditional blockchain-based mechanisms such as a Proof of Stake or Concept, the long wait times do not give every participant a democratic chance. A PoET mechanism enables every stakeholder to participate actively, making the system feel like an open lottery.

PoET in distributed ledger technologies

In many distributed ledger systems, there is a need for building trust among stakeholders. For instance, a distributed ledger service in government could involve land records. One can use PoET to create a secure and transparent government services system where citizens can access government services and track the status of their requests securely and transparently.

PoET in smart contract platforms

To understand how PoET mechanisms are crucial to smart contracts, let us take the example of a supply chain where smart contracts are crucial. You can use PoET to create a secure and transparent supply chain management system where all participants can track the movement of goods from producer to consumer. This can help increase efficiency and reduce the risk of fraud and counterfeiting.To many enterprises, decentralization or removal of power from a single source is a major benefit. By automating the decision-making power, enterprises can run 24/7. For example, in the financial services sector, a PoET mechanism helps create a tamper-proof environment, which only adds to customer trust.

PoET vs. other consensus mechanisms

PoET is important for blockchain systems as it offers several benefits that address some of the challenges other consensus mechanisms face. Besides enabling fairness, the PoET mechanism is energy-efficient, secure, scalable, and reliable at all times. These benefits make PoET a perfect match in decentralized smart contracts or distributed ledger-based technologies. However, the development of PoET as a mechanism is a recent phenomenon, and many blockchains use traditional consensus methodologies such as Proof of Work and Proof of Stake. Let us take a quickly examine the other methodologies to evaluate their pros and cons.

Comparison of PoET with other consensus mechanisms such as PoW and PoS

The PoET consensus mechanism used in advanced blockchain systems differs from other popular consensus mechanisms such as PoW and PoS. The PoW consensus mechanism requires nodes to perform complex computational tasks to produce and add a new block to the blockchain. Energy-intensive mechanism can lead to centralization if only a few nodes have the resources to participate. The PoS mechanism requires nodes to hold a certain amount of the network’s native currency on the crypto network in order to participate in the consensus process. This mechanism is less energy-intensive than PoW, but can still lead to centralization if only a few nodes hold a large portion of the network’s tokens.

Advantages and disadvantages of PoET

So far, PoET has been able to offer unbeatable energy efficiency since the mechanism does not require nodes to perform complex computational tasks. It provides a fair opportunity to nodes, enables security, and is highly scalable. It is a fast and efficient consensus mechanism that can handle large numbers of nodes and transactions, making it well-suited for large-scale blockchain systems.

How PoET differs from other consensus mechanisms

The PoET consensus mechanism comes with significant merits and some challenges. One of the biggest disadvantages of the PoET system is its dependence on the TEE. Should the TEE be compromised, the entire network could face downtime. Technical expertise in setting up the PoET consensus mechanism makes it complicated. Needless to say, PoET is a relatively new consensus mechanism and may require time to gain wider adoption and establish itself as a trusted solution.

PoET security

While PoET has significant advantages over any blockchain network, one must evaluate the security concerns before implementation.

The security of PoET depends on several factors, including the implementation of the consensus mechanism, the security of the TEE used to assign wait times, and the network’s overall security.

Security features of PoET

With a TEE, the PoET mechanism assigns wait times through a tamper-proof and secure process. The TEE is the heart of the blockchain system, which ensures the secure execution of code and protects sensitive information, such as wait times, from tampering or theft. Another security feature of the PoET mechanism is the random leader algorithm that determines the next block producer, which helps prevent centralization and ensures the network’s independence. Lastly, PoET is a decentralized consensus mechanism that does not rely on a single node or entity to validate transactions. This helps to ensure the security and integrity of the network by spreading the responsibility of validation across many nodes.

PoET’s resistance to Sybil attacks

In terms of resilience to Sybil attacks and network failures, PoET networks are generally robust due to their decentralized nature and the use of a TEE to assign wait times. However, like all blockchain systems, PoET networks are vulnerable to various types of attacks, such as denial-of-service attacks and network partition attacks, which can cause network failures or slow down the consensus process.

PoET’s resilience to network failures

To mitigate security risks, PoET networks implement additional security measures, such as firewalls, intrusion detection systems, and network segmentation. Additionally, PoET networks can regularly review their security posture and implement patches and updates as needed to address any vulnerabilities or security risks. In conclusion, while PoET provides a number of security benefits, it is important to maintain a comprehensive security approach to protect the network and ensure its resilience to potential threats.

Future of PoET

The future of PoET is bright, although it is a relatively new consensus mechanism in the blockchain space. One needs to wait to realize its future potential for improving blockchain systems. However, several factors suggest that PoET has the potential to become a valuable tool for improving the performance and security of blockchain networks.

Advancements in PoET technology and their impact on blockchain

Many blockchains are evaluating the deployment of additional techniques to reduce the complexity of PoET design and its implementation.

PoET has already established itself with its advantages despite very few takers in the crypto market. As of January 2022, only Hyperledger Sawtooth had reportedly deployed a PoET mechanism. Through its offering, Hyperledger Sawtooth offers enterprises an opportunity to build, deploy, and operate distributed ledgers. Their system enables participants to build a transaction-based update that can be shared with even untrusted parties. Given the success, many blockchain communities, including popular crypto, will likely embrace the PoET mechanism.

PoET in enterprise and industrial environment

In terms of enterprise adoption, some enterprises are considering PoET as a potential consensus mechanism for their blockchain systems. PoET has the potential to provide several benefits for enterprises, including improved performance, lower energy costs, and enhanced security. However, as with any new technology, there may also be challenges and uncertainties that need solutions before widespread adoption can occur.

In conclusion, PoET has the potential to play an essential role in improving blockchain systems. It is likely that we will see increased interest and adoption of PoET in the future, especially in the enterprise sector. However, it is still the early days for PoET. Much will depend on the continued development and refinement of the technology and its ability to meet the needs and demands of enterprise-level blockchain systems.


To enterprises actively considering a blockchain interface, PoET is a no-brainer. One of the crucial challenges of complexity and costs can be overcome through economies of scale. However, great advantages include energy efficiency and the random selection process that helps decentralization. The average crypto investor should also perceive PoET as an opportunity in scalable projects.


Is There a Proof of Elapsed Time Coin?

PoET is primarily used in Hyperledger Sawtooth. As of January 2022, there isn’t a cryptocurrency that uses PoET.

What Is the Difference Between Proof of Work and Proof of Elapsed Time?

PoW is a competitive work mechanism, where PoET is a random selection mechanism.

What Is Hyperledger Sawtooth?

Hyperledger Sawtooth is a distributed ledger—similar to a blockchain—designed for enterprise uses like supply chain and logistics. It could even be used for inventory management, accounting, or other business tasks that consume time and are prone to error.

Disclaimer: Crypto products and NFTs are unregulated and can be highly risky. There may be no regulatory recourse for any loss from such transactions. The information provided in this post is not to be considered investment/financial advice from CoinSwitch. Any action taken upon the information shall be at the user’s risk.

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