Zcash recently announced their new protocol upgrade, Blossom, which among many new developments will include “Harmony Mining”, which will enabling the network to utilize two proof-of-work algorithms.
The forum post described the feature as “a dual-proof-of-work scheme, where one algorithm is backwards compatible with current mining equipment, and another is designed to work well with GPUs on a temporary time scale”. The post went on to describe how the upgrade will allow the network to attract both ASIC and GPU miners “to make the Zcash ecosystem more resilient by spreading issuance and political influence among distinct kinds of stakeholders”. Currently, most GPU miners are crowded out by the more powerful ASIC miners.
The upgrade is scheduled to be release around October 28th, 2019, which would be about a year after the sapling release, which was the last upgrade.
Importance of decentralized and robust validation
The potential hash war that nChain and CoinGeek are threatening with their Bitcoin SV code against the Bitcoin ABC code supported by Bitcoin.com, Coinbase, Binance, and others highlights the need for decentralized mining and transaction validation methods. nChain chief scientist Craig Wright has been speaking heavily on twitter and other media outlets that he will destroy the Bitcoin ABC chain through a hash war. However, Craig Wright has also hinted at his plans to attack other proof-of-work cryptocurrencies and there has been the suspicious emergence of Shark Pool, which is claiming it will maliciously mine empty altcoin blocks.
The concerns highlight the importance of cryptocurrencies having a robust and decentralized validation system, such as the one Zcash is exploring. PIVX provides a potential alternative with its proof-of-stake system to validate and secure its blockchain, however, it has created a centralization problem since the top 10 and 100 wallet addresses contain over 25% and 46%, respectively, of the network’s wealth. Another potential solution to create a robust and decentralized cryptocurrency is to employ multiple algorithms. This is what Digibyte has done by harnessing 5 different hash algorithms; Sha256 and scrypt optimized for ASIC miners, while skein and groestl are optimized for GPU miners, and qubit is good for multiple types of hardware. The diversity of these validation methods can help mitigate the risks of centralization and a 51% attack by increasing the capital requirements needed to gain enough computing power or coins to attack the network.
Collateralized mining and other similar research could lead to a more attack-resistant network
Research into alternative and hybrid consensus mechanisms could lead to the development of a more robust protocol than current methods. Dash’s founder Evan Duffield laid out a plan to implement a system dubbed “collateralized mining” last year, which would effectively pair masternodes with mining equipment, removing the ability for an attacker to simply build or purchase hardware in order to attack the network. This plan has not, however, been recently verified by the Dash developers, and may no longer be in consideration for future implementation.
At present, Dash employs both traditional proof-of-work mining and a collateralized masternode network. When using InstantSend transaction locking, masternodes reject blocks in conflict with the lock, providing a dual security mechanism. While at present Dash uses traditional mining for consensus, the existence of a collateralized network already in place facilitates the implementation of a dual consensus mechanism if such a system is implemented. Under this hypothetical situation, an attacker would both need 51% of the mining hashpower and control over 51% of masternodes. As over half of Dash’s present supply is already allocated to masternodes, the possibility of gaining control over a majority of the network in the future is very slim and would likely require years of sustained efforts.
Update: A previous version of this article cited an older source which presented conflicting information. This article has since been updated.