What is Solana's Proof of History and How Does It Work?

Over the past few years we have seen decentralized applications (dApps) begin to grow. Developers have launched applications for a variety of use cases, including games and decentralized finance (DeFi) protocols. A problem arose when developers did not have control over applications. Most of the decentralized applications in the ecosystem today run on Ethereum, which is struggling to keep up with increasing demand. As a result, users of decentralized applications on Ethereum must endure increased gas fees and network congestion. Solana, a Blockchain protocol founded in 2017, has taken a step to address the long-standing issues that Ethereum has been grappling with.

What is Solana? Before we continue, let's understand Solana. Solana can be described as an advanced, open-source Blockchain project that aims to leverage the latest technologies and power the next generation of decentralized applications. The protocol was created by Anatoly Yakovenko in 2017 and aims to go far beyond the capabilities of existing popular blockchains such as Ethereum while keeping costs low. To achieve this, Solana uses the lightning-fast synchronization engine Proof of Stake combined with Proof of History, a hybrid consensus mechanism. Using this unified mechanism, Solana can in theory process more than 700,000 transactions per second without needing any scaling solutions. Solana focuses on providing a secure, highly scalable and decentralized platform that can support thousands of nodes without affecting transaction throughput and avoiding the challenges faced by competing Blockchains. Solana Blockchain is viewed by analysts as the most serious competitor to the Ethereum Blockchain and has earned the nickname of the Ethereum Killer.


Several components make up the Solana network. ● Proofof History: Time synchronization before consensus. ● Tower BFT: Practical Byzantine Fault Tolerance version optimized for Proof of History. ● Turbine: Block broadcast protocol. ● Gulf Stream: A Mempool-less transaction forwarding protocol. ● Sealevel: Parallel smart contracts. ● Pipelining: A unit of processing for validation optimization. ● Cloudbreak: Horizontally scaled account database. ● Replicator: Distributed ledger store


Problem of Timely Reconciliation Distributed systems face a significant problem when it comes to timely consensus. Some users have suggested that the most important feature of Bitcoin's Proof of Work is that it acts as a decentralized clock for the system. The Solana team believes that when it comes to time, Proof of Date is the solution. Several decentralized networks; solved the problem through reliable, centralized scheduling solutions. The problem is more pronounced in systems such as Blockchain, where network nodes cannot rely on an external time source. Hashgraph solves this problem through a “middle” timestamp, where every message seen by the network is signed and timestamped by a supermajority in the network. Each message goes to the vast majority of nodes in the network, and once it collects enough signatures, it needs to be propagated throughout the network. This process is quite cumbersome.


Solana and Proof of History Let's go into a little more detail about Solana's Proof of History consensus mechanism. Solana's Proof of Date is a method by which “time” can be incorporated into the Blockchain. This is done to reduce the load on network nodes when processing blocks. In a Blockchain, gaining consensus on the “time” at which a particular block was mined is as important as gaining consensus on the transactions contained in that particular block. This is very important because any observer on the network is informed about the order of operations via the timestamp. In Proof of Work, the block miner is the first miner who has to determine the appropriate nonce (a number that can only be used once), which takes a certain amount of computing power. Proof of History, on the other hand, uses Verifiable Delay Functions (VDFs). A VDF can be solved with only a single CPU by performing a series of steps. Since Verifiable Delay Functions do not allow parallel processing, it is easy to determine the time each step takes. Solana's distinctive feature is its unique variation of the Proof of Stake consensus system, augmented by another mechanism called Tower Consensus. Tower Consensus is a derivative of a system that allows distributed systems to reach consensus called Practical Byzantine Fault Tolerance (PBFT). The implementation of PBFT allows the implementation of a global time source on the Blockchain through Proof of History, which gives a record of previous events that have occurred on the Solana Blockchain and provides a permanent record. This can lead to a significant reduction in the processing power required to verify transactions, as timestamps of previous transactions do not need to be calculated. The biggest benefit for Solana is its significantly higher throughput, thanks to the Proof of History consensus mechanism. Theoretically, the Solana Blockchain can process more than 700,000 transactions per second, much faster than any other blockchain currently in operation.


Proof-of-History vs. Proof-of-Stake Both Proof of Stake and Proof of History have similarities as both consensus mechanisms are built on the same foundations. Both mechanisms use validators to validate transactions and create new blocks. The critical difference between the two is how time is calculated on each. Proof of Stake uses timestamp functionality on its own. This means that each node relies on the timestamp of the network, and since time must pass through the network first, the network can run slowly. Proof of History, on the other hand, uses the Verifiable Delay Function, which calculates time based on historical events. Historical events are analyzed and a summary function is created that can be verified by anyone. Each subsequent block created by the network contains this hash, which significantly reduces the time it takes to process transactions and allows Solana to scale.

Potential Topics Solana is the only blockchain that uses Proof of History, making the protocol incredibly scalable, but its consensus mechanism has not been tested on a large scale, meaning there may be undiscovered glitches that need to be addressed. Additionally, several vulnerabilities have been discovered in Solana, in part due to the Proof of History consensus mechanism. Solana's Proof of History helps Blockchain scale, enabling the processing of thousands of transactions per second. It offers a convenient option for developers who want to launch their decentralized applications. While Ethereum maintains its dominance in the DeFi and NFT space, its scalability issues are coming to the fore, and Solana is ready to challenge Ethereum's title as the industry lead