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.
Odyssey is primarily a decentralized sharing economy and peer-to-peer ecosystem, aiming to compete with and replace the likes of Airbnb and Uber. Odyssey dreams big - aiming to completely replace the concept of private ownership with an economy in which everything is shared and little is owned. It’s a long way from its goals, of course, but making peer-to-peer sharing more efficient with smart contracts is certainly a step in the right direction. The Odyssey website lists 9 advisors, with its primary two being Yi Shi, the CEO of Shanghai’s Avazu Holding, a leading global advertising platform, and Justin Sun, the backbone of the TRON cryptocurrency. The advisory team also includes Goh Jian Kai, founder and CEO of Southeast Asia’s cross-border payment solution system RateX. Odyssey has lofty goals, aiming to create a world where sharing is the norm and ownership or sharing monopoly doesn’t come in the way of people’s lives. A decentralized sharing platform where all service providers and customers are connected definitely sounds attractive. It’s a new currency, so it needs development to reach its goals. Of course, the fact that buying a large number of OCN tokens will not put a major dent in your pocket is a definite point in its favour.