Introduction to Grin Coin

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Grin coin is the first of its kind, a privacy coin application on the Mimblewimble blockchain, created with the Rust programming language. Rust is famous for its swiftness and scalability, which is why it is perfect for Grin and the Mimblewimble protocol. Mimblewimble itself is a new type of blockchain that guarantees privacy and offers enhanced scalability and speed over Bitcoin, which its supporters say it can supersede. Grin’s major aims include:

  • Complete privacy as its default
  • Scalable transactions
  • Tried and tested cryptography
  • Easy design for person to person transaction
  • Community-driven – aimed at decentralized advancement and mining

First Deployment of Mimblewimble

Grin is the first currency on the Mimblewimble blockchain, and as dictated by Mimblewimble, Grin transactions can be merged and therefore purged of information such as addresses, amounts, and other identifying information. Blocks in Grin, like MimbleWimble itself, contain no transactions, with the block resembling one big transaction. Spent outputs in Grin can also be safely removed from the blockchain, allowing a drastically reduced blockchain size. This means that Grin can scale with the number of users rather than the number of transactions.

Cuckoo Cycle

Grin utilizes the Proof-of-Work consensus mechanism, but with the ‘Cuckoo Cycle’ algorithm. This algorithm makes it ASIC resistant, preventing purpose-built mining equipment from mining it, something that other coins such as Vertcoin have also done to prevent centralization of mining operations as much as possible. The Cuckoo Cycle algorithm is also memory-bound, making it viable for CPUs to mine, something that is rare in cryptocurrencies these days. It is also apparently quantum resistant, something that may become important in decades to come.


Early criticisms of Grin and the Mimblewimble protocol were that two users needed to be online at the same time to allow a transaction, but this is actually false – a transaction can be sent and received at different times, just like a regular transaction. Overall, Grin represents the first step in a new and interesting path for cryptocurrency and blockchain, where privacy is complete and impenetrable. Whether Grin and the Mimblewimble protocol take off only time will tell, but even if the protocols themselves go nowhere, the technological advancements made in their design may feature strongly in the future.