Although it may be hard to imagine, cryptocurrencies are far older than Blockchain technology. Most of us look at Bitcoin as the first cryptocurrency, although it is only the first Blockchain-based currency. Cryptocurrencies like B-Money and BitGold existed prior to Bitcoin, however, these didn’t really go far, especially when judged against Bitcoin.

The problem with cryptocurrencies conceived before Bitcoin was their centralized structure. Without Blockchain technology, there was no “decentralized, immutable, transparent” ledger in which transactions could be recorded, leading to a centralization. Yet it looks like Blockchain may not be the be-all, end-all of digital currency technologies.

Recently, a new form of crypto has emerged that leverages the Directed Acyclic Graph (DAG) organizational model for the structure of its decentralized ledger, allowing old problems to be solved and new features to be added.

Today, we’re going to take a look at the technology that can potentially replace the Blockchain itself and some of its current implementations.

Although the implementations that we are going to discuss today are new, the concept is not. In a 2013 paper dubbed “Accelerating Bitcoin’s Transaction Processing. Fast Money Grows on Trees, Not Chains,” the authors Yonatan Sompolinsky and Aviv Zohar introduce the GHOST protocol which proposes a change to Bitcoin’s structure from a Blockchain into a tree, reducing confirmation times and improving security. Although this change has not been implemented in Bitcoin, other cryptocurrencies are using the DAG-based system successfully. Let’s meet them!

src:
https://cointelegraph.com/news/future-of-digital-currency-may-not-involve-blockchains