The Peercoin network activated in 2012 and is one of the first cryptocurrencies to ever be released. It is responsible for inventing proof-of-stake consensus, which makes it the first efficient and sustainable public blockchain technology. Peercoin was inspired by bitcoin, and it shares much of the source code and technical implementation of bitcoin. The Peercoin source code is distributed under the MIT/X11 software license. Unlike bitcoin, Namecoin, and Litecoin, Peercoin does not have a hard limit on the number of possible coins, but is designed to eventually attain an annual inflation rate of 1%. There is a deflationary aspect to Peercoin as the transaction fee of 0.01 PPC/kb paid to the network is destroyed. This feature, along with increased energy efficiency, aim to allow for greater long-term scalability. With the same encryption algorithm as Bitcoin (SHA-256), Peercoin is 100 times more energy efficient. Transactions in the Peercoin network are faster and cheaper. If there were not fierce competition on the cryptocurrency market, Peercoin would probably have long since become one of the most important cryptocurrencies. But in 2014 and 2015, however, there were many other interesting innovations in the cryptocurrency market that outperformed peercoin in a number of important properties. In contrast to DASH, Peercoin could not offer anonymity and the transactions in Dogecoin were even faster and cheaper than those of Peercoin. PoS technology ceased to be an advantage of peercoin and PoS continued to spread to other cryptocurrencies. The interest of the users drew it to the side of the minings on the CPUs and GPUs, then to the side of the Smart Contracts and PPC began to get a little forgotten. The Peercoin Team believes that adapting blockchains for wide scale use only through on-chain transactions will negatively affect the decentralization level and security of the network over time, therefore we choose to develop the Peercoin blockchain as a base layer settlement network with a sole focus on securing all forms of value recorded into the chain. This can be accomplished through Peercoin's philosophy of preserving and maximizing decentralization (which increases security) by developing the majority of features and technologies on top of the blockchain, rather than directly into the blockchain protocol itself. Thus the Peercoin Team focuses on developing second layer protocols and sub-networks that can interact with the base layer blockchain to adapt it for wide scale use and improve functionality such as tokens, smart contracts and high speed low cost transaction processing. In this way, Peercoin will act as a secure and censorship resistant base layer for the future blockchain connected world.
Grin coin is a private & lightweight open source project based on the mimblewimble blockchain implementation. MimbleWimble is a lightweight blockchain protocol proposed by anonymous author that goes by the name Tom Elvis Jedusor (inspired by Harry Potter) in July 2016. Since then, the proposal has gained a huge following among Bitcoin and privacy advocates. Unlike bitcoin or ethereum, there are no addresses in Grin. In order to transact using Grin, both wallets must communicate with each other online with the results broadcasted to the network. Another key different is that transaction history (sender, receiver, amount) will not be recorded on the blockchain. Due to the removal of these information from the transaction, the data size remains small and that keeps the blockchain lightweight. New nodes can easily join the network without having to download a large blockchain. Grin coin was launched without an ICO, fundraising, or pre-mine. Developers around the world contribute openly with the goal to ensure the coin distribution remains as fair as possible. There are 2 popular wallets widely available to interact with the Grin network. Grin core wallet: https://www.coingecko.com/buzz/how-to-use-grin-wallet-to-send-receive-grin-coins Wallet713: https://www.coingecko.com/buzz/how-to-use-grin-wallet713-to-send-and-receive-grin-coin-step-by-step-guide The consensus algorithm used by Grin is the Cuckoo Cycle proof-of-work based. There are 2 hashing algorithms involved with Grin. Cuckoo-29 is meant for GPU mining while Cuckoo-31 is meant fo ASIC mining. This is a deliberate design to encourage miners to eventually move into ASIC mining for efficiency while keeping it fair at the beginning of the launch. Grin coin has launched its mainnet on 15th January 2019 and is now available for mining and trading.