Grin is a newly emerging digital currency initiative prioritizing privacy, growth potential, and seamless fungibility, achieved through strategic implementation of the MimbleWimble blockchain alongside various optimizations. MimbleWimble represents a captivating, minimalistic blockchain framework first put forward by Tom Elvis Jedusor in mid-2016, now gaining popularity among supporters of Bitcoin and privacy-centric crypto solutions.
Grin is an open-source project that offers a refreshing list details a list of functions it won't perform, diverging significantly from contemporary trends in the crypto landscape. To fully grasp Grin's functionality, one must first delve into the workings and benefits of MimbleWimble.
What is MimbleWimble?
Initially proposed envisioned in 2016 by Tom Elvis Jedusor, which was then refined by Adam Poelstra a few months afterward, MimbleWimble is a blockchain methodology that integrates multiple pioneering techniques to transform Bitcoin transaction formation processes and condense the blockchain size.
MimbleWimble specifically targets two critical components:
- Privacy
- Scalability
Thanks to its inherent privacy attributes, both MimbleWimble and its Grin counterpart boast exceptional fungibility.
Privacy
Under MimbleWimble, transaction information remains concealed, yet validity is intact despite lacking visible addresses and keeping transaction amounts entirely obscured. This method capitalizes on Elliptic Curve Cryptography (ECC) to formulate secure transactions through zero-sum verification combined with private key possession.
Read: What Is Elliptic Curve Cryptography?
Validation of transactions in MimbleWimble requires ensuring that the sum of transaction outputs minus the inputs consistently equals zero. This is achieved with Confidential Transactions that confirm no double-spending or unauthorized fund creation, while simultaneously keeping amounts secret. The foundation for this concept originates from Confidential Transactions (CTs), developed by Greg Maxwell.
In MimbleWimble, ownership verification leverages blinding factors, which are essentially the user's private keys linked to the transaction kernel's excess values. These blinding factors enable users to showcase ownership of transaction value discreetly.
The principle of transaction validation without revealing exchanged values echoes techniques zero-knowledge proofs and RingCTs utilized in ZCash and Monero, respectively.
Conversely, MimbleWimble eliminates traditional addresses; the two wallets involved interact directly to share data, wherein the recipient designs and conveys an address to the sender. This exchange remains visible solely to participants, with information non-accessible to third-party entities. Interaction does not necessitate simultaneous online presence.
Moreover, blockchain blocks do not explicitly detail separate transactions (even in obfuscated form, i.e., Monero ), they consolidate into unified transactions mixing inputs and outputs. A block examination reveals no transaction-specific insights. Within MimbleWimble, transactions assume a non-interactive CoinJoin variant, unable to be separated.
In essence, nodes verify transaction legitimacy without exposing transfer values, eliminating addresses, and ensuring zero identifiable transaction details.
Scalability
MimbleWimble’s scalability strategy is straightforward, bypassing complex layer two solutions or increased on-chain capacity. Instead, it enhances efficiency by scrapping obsolete and redundant transactions from the blockchain.
Specifically, this method involves gradually removing spent blockchain inputs by combining intermediary transactions, drastically minimizing blockchain size through a strategy called cut-through. A MimbleWimble transaction comprises the following components:
- A collection of inputs referencing and consuming prior outputs
- A set of new outputs ( Pedersen Commitments )
- A Transaction Kernel encompassing kernel excess along with transaction signature.
In MimbleWimble blocks, cut-through transactions are only manifested by their transaction kernels, with all outputs appearing indistinguishable, primarily manifesting as large, indistinguishable numbers. According to Grin’s MimbleWimble introduction, Github :
“Like a transaction, a block only needs verification of proven ownership (from transaction kernels) and confirmation that the block does not introduce any extra money supply (besides permissible coinbase allowances). Consequently, matching inputs and outputs become redundant as they balance each other out in the overall sum….Furthermore, the structure of transactions becomes obsolete, and the input-output sequence no longer matters, yet the total output sum minus inputs in this block remains zero.”
Therefore, discerning particular input-output matches becomes impossible while maintaining transaction validation capability within a block. Nodes can further authenticate blocks by correlating mined monetary sums with total supply.
MimbleWimble’s pruning capability significantly increases the protocol's scalability by allowing users to swiftly synchronize with the network. The entire chain state retains validity akin to a full node, irrespective of users not holding most historical blockchain data.
What is Grin?
Grin embodies a MimbleWimble-based cryptocurrency focusing on privacy, fungibility, and scalability. Technical descriptions of Grin largely overlap with MimbleWimble, so it's essential to highlight other factors like consensus and monetary policy .
Grin inherits MimbleWimble's privacy and fungibility traits, featuring no addresses or transaction amounts, with transactions integrating to eliminate intermediary information. Similarly, Grin blocks — akin to MimbleWimble — lack visible transactions, resembling singular extensive transactions.
In Grin, spent outputs can be safely discarded, considerably shrinking the blockchain size. This enables users to download and authenticate the blockchain much more rapidly than in other cryptocurrencies. Consequently, Grin scales proportionally with user numbers instead of transaction volumes.
Read: Our Guide to Mining Grin Coin
Introducing Grin’s Cuckoo Proof-of-Work System
Grin refrains from employing avant-garde consensus models like proof of stake, instead opting for the foundational PoW approach utilizing Cuckoo Cycle algorithm.
Cuckoo-style PoW, chosen to avert Bitcoin’s 'hardware arms race' by resisting ASIC dominance. Cuckoo Cycle, a memory-intensive algorithm, is feasible for CPUs, enhancing decentralization.
Mining difficulty adjusts according to current hash power, stabilizing block production at around 60-second intervals. Detailed Cuckoo Cycle PoW insights are available in the white paper by John Tromp and Grin mining on the Grin Github .
Grin’s Dandelion Implementation
Grim implements the Dandelion Protocol for boosting network layer privacy through improved transaction message dissemination. The Dandelion Protocol guards against recent academic paper-documented attacks aimed at deanonymizing users by correlating IP addresses with transaction movement from the origin.
Grin incorporates a tweaked Dandelion version to collate transactions, complementing MimbleWimble’s transaction amalgamation.
Read: What is The Dandelion Protocol?
Monetary Policy of Grin
Cryptocurrency's recent exciting aspect is monetary policy, and Grin seeks to function more as a transactional medium than a value reserve, diverging from Bitcoin. In pursuit of this, a monetary framework was devised to stabilize currency value.
Grin uses a linear supply schedule where inflation persists due to unlimited supply, prompting spending over holding. Grin's initial high inflation rate dips below 10 percent after a decade, tapering off to near-zero. Nonetheless, the block reward remains constant.
Myles Snider offers an excellent analysis regarding Grin’s monetary approach consequences.
Current Status of the Project
Grin released its Testnet V4 was quietly pre-released the previous month, with an anticipated full launch slated for 2019. Despite featuring some of the industry's most groundbreaking technologies, Grin remains discreet outside mainstream high-profile projects.
Privacy advocates and Bitcoin aficionados eagerly await Grin. MimbleWimble enjoys considerable recognition for its technical merits in cryptocurrency, lending Grin attractive prospects by leveraging the MimbleWimble protocol.
Grin is also compatible with Schnorr signatures capable of generating multi-signature outputs. Widely admired, Schnorr signatures are anticipated to be integrated with Bitcoin within 2019.
Aside from its technical framework, Grin's intriguing monetary policy holds fascinating implications for cryptocurrency's evolution towards a currency role, rather than a value store.
Grin is open to contributions from developers, expected to remain a compelling observation as it continually advances.
4Comments
A comparison between Grin and another MimbleWimble project, Bean, would be intriguing.
Lol. Not really.
Why, such a non-informative response leaves individuals like me, who lack in-depth project knowledge, feeling excited!
Blockchains devoid of older nodes cease to exist as true blockchains. It's perplexing how many fail to grasp this concept, even skilled developers seem to have lost perspective.