Part 5: Technical introduction - What is Pow?


Some view Proof of Work (PoW) as environmentally taxing, given its high carbon footprint and energy expenses. Others see it as a process where mining difficulty adjusts based on the number of miners participating in solving a cryptographic puzzle within the Poisson process. A process where miners aim to brute-force guess the correct nonce, create a new block name, and earn a reward.
Most articles or books will probably describe PoW, a decentralized consensus mechanism where participants within the network must dedicate computational effort to decipher an encrypted hexadecimal number. This process is colloquially known as "mining," and those engaged in it earn rewards for their computational contributions.

But more fundamentally, PoW is a technological primitive used to identify and sign the way for participants in a consensus. Bear in mind, though, that consensus protocols (CPs) have been here for decades, if not more, and it is not a term that arrived with blockchains.

PoW was pioneered with Bitcoin, and the primary objective behind its use was to eliminate the need for a predefined set of participants. Previously, in the context of CPs, it was assumed that there were a certain number ('n') of nodes with known indexes (names). These nodes were responsible for agreeing on the history of events, especially in conflict scenarios.

Since the nodes were named according to their cardinality, a consensus protocol could be established among them. This was typically achieved through "leader selection," where a leader was chosen to resolve conflicts.

This decision, however, is not trivial and can be manipulated. Nevertheless, it's important not to assume that the leader node is always the correct one. It could potentially be a compromised or faulty node. Therefore, the assurance lies in not assuming the correctness of a node but in guaranteeing that the system reaches a consensus on the accurate history of events and their chronological order within the system.

The primary role of PoW extends beyond just shaping economic dynamics, although that aspect is indeed significant. PoW, as well as the core concept behind Nakamoto's consensus and Satoshi's Bitcoin, was intended to mimic the process of reaching consensus without prior knowledge of the number of servers in the network, their identities, global locations, or operators. Despite having limited information about the system, certain assumptions are made, and under these conditions, the consensus is achievable through the protocol's selection of the longest chain.

With Bitcoin, the most famous PoW-based chain that uses the longest-chain rule, there is, somewhat shockingly, a chain of blocks.

Every 10 minutes, a new block full of transactions is mined and stamped using the PoW mechanism and added in front of the latest block. However, what happens when conflicting transactions create a block with a different name?

Conflicts in Bitcoin look like a fork in the chain. This leads to a situation where the linear structure of the blockchain results in a "tree of blocks." The longest "branch" (chain) of the "tree" is the only one that is preserved, and off-the-main-chain blocks are discarded.

This is blockchain in 2009 and what was proposed in Satoshi's Bitcoin white paper as the Nakamoto Consensus.

But now......BlockDAGs, PoW, Kaspa, and community participation present a story about fulfilling Satoshi Nakamoto's original vision.

But how can a blockDAG, a blockchain that needs to be untangled from a graph to a linear structure, be a game changer in distributive ledger technologies?

Let's meet in the next episode. Until next time!