About Grin and MimbleWimble

The idea that changes must be made to the bitcoin network and protocol to achieve scalability at a global level is nothing new. Bitcoin is slow, clunky, mediocre and sometimes costly to transact. As we often discuss here at CoinSpot, the introduction of both SegWit and Lightning Network (LN) have done a lot to remedy this – but what if there was a better solution that could reduce not only the information needed to continue using the blockchain, but actually the size of the blockchain diminish as time went on? Better yet, what if it could do this while simultaneously anonymizing every transaction it captured?

That's what Grin and MimbleWimble are trying to achieve, and so far they're off to a pretty good start. In this article, we will discuss both topics one by one to give crypto users a better idea of ​​what is happening and help them understand why they are so important. It was not an easy task and to really understand how these concepts work requires an advanced knowledge of cryptography as applied to cryptocurrencies and the blockchain. We'll cover MimbleWimble first.

What is MimbleWimble?

In essence, MimbleWimble is a blockchain design quite different from the bitcoin blockchain and all the others, for that matter. What does the word 'MimbleWimble' mean and where does it come from? From the Harry Potter series, "Mimblewimble" is a spell that binds a person's tongue to prevent them from talking about a specific topic; more specifically, to prevent them from casting another spell. This refers to the fact that by design all sender, recipient and transaction information is anonymized and cannot be inferred from looking at the blockchain. These features make MimbleWimble extremely unique in terms of blockchain architectures and make it arguably the most privacy-focused ledger for a cryptocurrency ever developed.

One of the other interesting things about MimbleWimble is that it can be implemented as a sidechain or 'soft fork' (a backwards compatible fork) in bitcoin itself, meaning it doesn't necessarily have to be a competitor to bitcoin, but rather a solution to the bitcoin scaling problem.

MimbleWimble blockchains are also quite smaller than traditional blockchains, which is accomplished by reorganizing and streamlining data deemed essential to the blockchain's function. For example, instead of including public signature data for every input and output in a transaction, this data is all represented as a single value known as an "elliptic curve point." This value cannot be generated other than by the direct combination of all public keys involved in a transaction.

In addition, all consumed outputs are removed from the blockchain, keeping it lean and manageable. This idea was first expanded by Bitcoin Core developer Gregory Maxwell, known as CoinJoin. While it was never actually implemented in bitcoin, the basic idea was this:

Sender A sends 1 BTC to receiver B and then B sends 1 BTC to receiver C before confirming the first transaction. Does the blockchain really need to know that B ever held 1 BTC to continue functioning? The answer is: no. This idea can be spread to a series of senders and receivers who have related inputs and outputs that have yet to be confirmed by the blockchain. As explained by Maxwell in a Bitcointalk forum post:

'This transformation is lossless with respect to the final coin ownership, but the intermediate transactions were cut-through. This works even if the original coin ending up in the final outputs came from multiple parties, as they can coinjoin to preserve the final outcome. Because the replacements are atomic and consume the original inputs this transformation is safe, assuming people in the middle can handle any accounting complications that arise. (Eg figuring out that their payment really was completed). So you'd want to have a way of signaling 'I permit you to conflict this transaction with one that pays its children, if you can figure out how'.

So, as applied to MimbleWimble, this means that data related to consumed outputs can be completely wiped from the blockchain, not only to keep the blocking of the blockchain low, but actually allow it to shrink in size as multiple exhausted outputs at once. be removed. Only a small piece of data (known as a kernel, which is about 100 bytes in size) from each transaction must be kept for a MimbleWimble blockchain to function and keep accurate records of who owns what.

For MimbleWimble to work successfully as a ledger, the exact order of transactions does not need to be publicly verified because the total sum of inputs and outputs must always equal zero, plus the number of new coins mined in each block. As with bitcoin, coins cannot be created artificially by manipulating blocks and transactions – unless the network is 51% attacked and the majority of nodes replace the correct blockchain with a modified version.

The author of the original MimbleWimble white paper referred to himself as "Tom Elvis Jedusor" (which is the name of Harry Potter character Voldemort in the French edition of the novel series). The anonymous author posted the white paper using a Tor (“.onion”) website that was removed long ago, making it impossible to find out where the site was located or who created it. However, the idea was so compelling that it immediately sparked interest among several Bitcoin Core developers who began testing its validity and feasibility as a blockchain for a cryptocurrency.

What is Grin?

Grin is a cryptocurrency that uses an implementation of the MimbleWimble protocol. A few months after Tom Elvis Jedusor's appearance, another Harry Potter-related pseudonym appeared on the same IRC channel to announce that they had developed the first open source implementation of MimbleWimble, namely Grin. A repository published on GitHub by "Ignotus Peverell" contained the software needed to test a beta-net version of Grin, and Grin was born.

Just over two years and two months later, after a very thorough period of beta testing and development, the Grin mainnet launched on January 15 with the original MimbleWimble white paper as written by Jedusor extended by Andrew Polestra of WPS Software. Although Jedusor and Peverell are accredited with the invention of MimbleWimble and Grin, it was Polestra's guidance and perseverance in realizing the idea that had brought Grin to fruition. In its updated version of the white paper, Polestra introduces MimbleWimble and Grin as follows:

Mimblewimble is a design for a cryptocurrency whose history can be compacted and quickly verified with trivial computing hardware even after many years of chain operation. As a secondary goal, it should support strong user privacy by means of confidential transactions and an obfuscated trans30 action graph. This precludes such functionality as zero-knowledge contingent payments, cross-chain atomic swaps and micropayment channels. Further research is needed to emulate these functionalities on top of Mimblewimble.

In a nutshell

In short, Grin and MimbleWimble are revolutionary new developments in cryptocurrency that make the most of the cryptographic principles initially used by bitcoin. Grin is a drastic departure from pre-existing Proof of Work coins and solves some of the key issues Bitcoin faces: scalability, speed, and privacy. That said, it is still in its infancy and has a long way to go before it can prove itself as a technically sound, reliable and widespread model for a cryptocurrency.