Cryptocurrencies Grin and Beam on MimbleWimble: features and differences, mining and wallets

January 2019 was marked not only by the continuation of the bearish trend in the cryptocurrency market, but also by the launch of two new projects that attracted increased attention and could potentially occupy an important place in the entire ecosystem of digital assets.

We are talking about the anonymity-oriented cryptocurrency of users Grin and Beam – both are based on the MimbleWimble protocol , but have their own distinctive features and features. Let us see what the main differences between Grin and Beam are and what prospects these projects have.

MimbleWimble protocol

First we need to remind you what the MimbleWimble protocol is. His presentation took place in October 2016 at the Scaling Bitcoin conference in Milan, several months after the original white paper of the proposal was posted on Bitcoin developer channels.

The author of the proposal is an anonymous developer under the pseudonym Tom Elvis Jedusor (Volan-de-Mort name in French editions of Harry Potter novels). The very name MimbleWimble refers to one of the magic spells in the works of JK Rowling, which binds the language of a person to prevent him from talking about a specific topic.

“I called my creation MimbleWimble because it is intended to prevent the blockchain from being able to disclose information about users,” the source document says.

The concept of MimbleWimble uses the same method of elliptic curves when signing transactions, which is the basis of Bitcoin , as well as some features of the Confidential Transactions and CoinJoin – two solutions aimed at ensuring the privacy of users.

Both solutions at one time suggested the developer of Bitcoin Core Gregory Maxwell. It is therefore not surprising that MimbleWimble almost immediately attracted the attention of several well-known cryptographers, including Andrew Poelstra from Blockstream, who presented his own improved version of the protocol .

It was originally supposed that MimbleWimble could be integrated into the Bitcoin code base via softfork or exist as a sidechain, but, as Bitcoin Core developer and co-founder of Bitcoin Core Peter Velle later explained , this is associated with certain difficulties.

“Implementing MimbleWimble in a bitcoin in a backwards compatible way will be a daunting task. I am not saying that this is impossible, but it would be difficult. I see it as an experimental separate circuit or as a sidechain … MimbleWimble has some weak points. In particular, it does not have a script language. As you know, scripting languages are very well suited for experiments, but they are not private enough. MimbleWimble has a different approach – it provides very good privacy, but it does so at the expense of other properties, ”said Peter Velle, in particular.

The lack of a scripting language (scripting language) in MimbleWimble also means that there is no space left for innovations such as payment channels ( Lightning Network ) and atomic cross-platform atomic swaps that are already running on the Bitcoin network.

At the same time, an important feature of MimbleWimble is the ability to create a fundamentally different transaction structure and a smaller blockchain than Bitcoin. Through the use of Confidential Transactions, transactions are opaque: the addresses and amounts of transfers are hidden from outsiders.

Also in MimbleWimble, there are no addresses familiar to Bitcoin users – instead, two purses exchange data with each other. This data is visible only to participants in the transaction, and they don’t even have to be online at the same time.

This is solved by the fact that the blocks do not list the individual transactions, but are combined into one transaction with mixed inputs and outputs. Thus, viewing a single block will not give information about individual transactions. In fact, transactions in MimbleWimble are a variant of the CoinJoin coin mixing technique.

As a result, the developers came to the conclusion that the creation of a separate coin would be the best solution, and since the presentation of the protocol, there appeared two of its implementation, each of them has different approaches to the community, philosophy, financing and technical specifications.

Cryptocurrency Grin

The first and most famous implementation of MimbleWimble called Grin was released a few days after Andrew Poelstra introduced his version of the protocol. Its author was also a developer who wished to preserve anonymity under the pseudonym Ignotus Peverell (another Harry Potter hero), who published a partial implementation of the protocol in Rust, as well as his vision of the project’s philosophy.

In March 2017, he presented a technical introduction to Grin and MimbleWimble, which today serves as the main source of protocol specifications. In November 2017, the first test network of cryptocurrency was launched, and on January 15 of this year, the launch of the main network.

Cryptocurrency Beam

Another implementation of the protocol was the Beam project. It is implemented by a startup of the same name, headed by Israeli businessman Alexander Zaydelson. In its structure, Beam differs markedly from Grin, with its philosophy and spirit of opensource, impregnated with the ideas of a cipherbunk.

Work on the Beam began in March 2018, and on January 3, 2019, the official launch of the main network of this cryptocurrency took place. In addition to a well-built development team and engineers, Beam also has technical differences from Grin, including a financing model, monetary policy, and a mining algorithm.

The key differences between the Grin and Beam coins

Below are the main differences between the projects Grin and Beam .

• The main implementation of Grin is written in Rust, while the Beam codebase is written in C ++.
• The Grin development team made a choice in favor of the opensource management model, relying on donations, at the expense of which the development is underway. The project did not conduct an ICO, did not lead a premine and is not controlled by any company, foundation or individual. The Beam team even before the launch of the main network conducted a round of private financing, and also (by analogy with Zcash ) created a special fund, which transfers 20% of the mining award.
• Grin’s monetary policy is built on an inflationary model that assumes an endless issue of coins and a constant reward for the block found (60 Grin). Block creation time is one minute. Beam adheres to a deflationary model with limited emissions (about 263 million coins) and periodically halving the reward to miners. When the network was launched, the reward size was 100 coins, the first reward reduction twice a year, and then every four years.

Cryptocurrency anonymity

One of the main problems of users' privacy, which many cryptocurrencies face, is the ability to track transactions as they are added to the memory and distributed across the network, as well as the binding of the transaction to the source IP addresses. This information can be used to de-anonymize users even in networks with a high degree of confidentiality of transactions.

To increase confidentiality when distributing transactions, the MimbleWimble protocol, in addition to Confidential Transactions, also offers the Dandelion scheme, which both projects have adopted. In this scheme, transactions are distributed in two phases: the anonymity phase or the “trunk” (Stem) and the distribution phase or the “fluff” (Fluff).

Grin implementation allows you to aggregate and cut through transactions in the “trunk” phase, thereby ensuring an even greater anonymity of transactions before they spread during the “fluff” phase. In addition, the Beam contains “bogus” transactions that are added at the “trunk” stage to compensate for situations where real transactions are unavailable.

It should be noted another unique feature of BEAM – the ability to audit transactions without disclosing data to the public. To this end, the project team has developed a wallet that generates additional pairs of public and private keys specifically for audit purposes. These signatures are used to mark transactions, and only the verifier who has been provided with the public key can identify these transactions. The auditor cannot independently create transactions with this marking, which allows companies to provide information on their transactions for verification without jeopardizing their confidentiality.

Mining Grin and Beam

Both projects declare their intention to resist ASIC mining , while choosing different hashing algorithms and an initial mining approach.

Initially, the Grin network planned to use the Cuckoo Cycle, an alternative Proof-of-Work mechanism that is considered ASIC-stable due to the limited memory latency. However, in August 2018, developers announced the likelihood that ASIC-mining will be available for Cuckoo Cycle already at the start of the network.

To solve this problem, as well as taking into account previous statements by representatives of the project about the inevitability of ASIC mining, it was proposed to use two algorithms of PoW at the initial stage – one friendly ASIC (Cuckatoo31 +), the other – mining-resistant on such devices (Cuckaroo29). This is supposed to balance the mining reward over the 24-hour period between the two algorithms.

The proposal was adopted in September 2018 – Cuckatoo32 + became the autofocus algorithm, which will gradually increase memory requirements. Also, the developers plan to actively develop a decentralized community of mining on the GPU and conduct regular hard forks.

The Beam team, meanwhile, preferred the Equihash Proof of Work algorithm, which was created to increase the efficiency of mining on conventional graphics processors .

A month after the launch of the Beam network, the largest mining pool, as statistics show, is sparkpool.com (about 40% of the total hashrate). In the first weeks of the project, bepool.org ranked second, but later its share in the network fell to 16%, and leafpool.com (23%) and F2Pool (19%) went ahead.

The mining landscape in the Grin network is more variegated and is represented by about a dozen different mining pools . The most famous among them are grinmint from the company BlockCypher and MWGrinPool. In general, it is difficult to draw any definite conclusions – the network has only been working for a couple of weeks, and there are also certain infrastructural and technical problems that make Grin’s mining process difficult.

Exchanges where Grin and Beam tokens are traded

BEAM, although it was launched a little earlier, is currently trading on just a few small exchanges, as well as on the decentralized Bisq exchange.

Grin is represented more widely in this respect, and more well-known platforms are gradually added to the coin ( KuCoin , OKEx , Gate.io). Both assets are also represented at CoinMarketCap ( Beam and Grin ), although it’s too early to say that their price has managed to find a balance.

Thus, Grin and Beam are two open source projects based on the MimbleWimble protocol, which, despite their external similarity, have their own unique functionality and adhere to different approaches. It will probably take at least several months before the market chooses a “winner”, and it is still difficult to predict the outcome of this rivalry.

Be that as it may, the emergence of these two projects also provides an opportunity “in combat” to try to give answers to some important questions that have long been occupied by the minds of the cryptocurrency community.

In addition, it will be very curious to see how successful their attempt to take a place in the market of privacy-oriented cryptocurrency will be, where players such as Zcash and Monero are already present, as well as louder and louder declare themselves their own improvements to the Bitcoin protocol in this direction.

Publication date 05/02/2019
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