Originally conceived by Vitalik Buterin, Ethereum can be characterized as being an open technology platform upon which developers can build and launch decentralized applications (or dapps) using smart contract technology. Ethereum’s native asset is known as Ether, it serves as a fee for computations that are executed on the network. That fee is calculated in gas, but is paid for in Ether. Ether also functions as an incentive mechanism for cryptocurrency miners to secure the network. Underpinning the entire protocol is the Ethereum algorithm for proof of work mining, known as Ethash.
Proof of work mining functions as a tool that is used to secure distributed networks and process blocks of transactions on the blockchain. Proof of work mining involves taking data from a block header to form an input, and repeatedly hashing that input using a cryptographic hashing algorithm. This produces an output of a fixed length, which represents the hash value. Miners will hash variations of the input data by including a different nonce each time the input data is entered into the algorithm. In the case of Ethereum, the algorithm used for this process is Ethash.
Ethash is a proof of work algorithm that is a modified version of a precursor algorithm known as Dagger-Hashimoto. With Ethash, the output formed in the hashing process must result in a hash value that is below a certain threshold. This concept is known as difficulty, and it involves the Ethereum network increasing and decreasing the threshold in order to control the rate at which blocks are mined on the network. If the rate at which blocks are found increases, then the network will automatically increase the difficulty i.e. it will lower the network threshold so that the number of valid hashes capable of being found also decreases. Conversely, if the rate of discovered blocks decreases, the network threshold will increase to produce a higher number of correct hash values that could be found. With the Ethereum algorithm, the difficulty dynamically adjusts such that, on average, one block is produced by the network every 12 seconds.
A miner that successfully discovers a block that can be added to the blockchain receives:
A static block reward consisting of 3 Ether.
All of the gas spent within the block, in other words, all of the gas that has been consumed by the execution of all the transactions that are contained within the block. This gascost is awarded to the miner’s account as part of the proof of work mining process.
An extra reward for including Uncles as part of the block. Uncles that are included in a block by a proof of work miner receive 7/8 of the static block reward, which is 2.625 Ether.
Ethash and ASIC-Resistance
Ethash is based around a large, randomly generated dataset known as a DAG (Directed Acyclic Graph). The DAG is updated once every 30,000 blocks, and the current DAG size of Ethereum is, at the time of writing, currently 2.84 GB. The DAG will continue to grow as the blockchain grows.
Mining on Ethash involves fetching random data from the dataset (the DAG), computing some randomly selected transactions from N block, and then returning the hash of the result. This means that a miner will be required to store the entire DAG in order to be able to fetch random data and compute randomly selected transactions. As a result, the proof of work mining process on Ethereum is one that can be characterized as being memory-hard or memory-bound. Memory hard refers to a situation in which the time taken to complete a given computational problem is primarily decided by the amount of memory required to hold data.
This means that the vast majority of a miner’s efforts will be expended on reading the DAG, instead of computing data fetched from it. This is intended to make Ethash ASIC (application-specific integrated circuit) resistant, as the large memory requirement of mining on Ethereum means that large-scale miners gain little benefit from packing terabytes of memory into their devices. This is because smaller miners can achieve the same effect by simply purchasing a large amount of memory holding devices, as the energy cost of memory is comparable for both ASIC chips and any physical device capable of storing memory.
Ethereum’s proof of work model can be contrasted to models such as Bitcoin, which is based on SHA-256 hashing. In the case of Bitcoin for example, its proof of work scheme is compute-bound, meaning that the time taken to complete a computational task is decided primarily by the speed of a computer’s central processor. Given the fact that Bitcoin’s mining algorithm requires a simple SHA-256 computation, we have seen the emergence of ASIC chips that have been configured and designed for the sole purpose of computing billions of SHA-256 hashes. This has made it virtually impossible for miners with general purpose CPU and GPU hardware to compete, as ASIC chips are much more efficient in computation.
To conclude, in an attempt to make the mining process a more egalitarian one, Ethash is a memory-hard proof of work algorithm that has been designed to be ASIC-resistant. It is also important to note that there are plans to transition Ethereum’s consensus algorithm from proof of work to proof of stake, which would make mining on Ethereum, in its current form, obsolete.
Ethereum is an open platform technology with a decentralized public blockchain. Developers can build and launch their own decentralized applications, or dapps, using smart contracts written in Ethereum’s own programming language, Solidity. A current popular type of decentralized applications are Ethereum games; these are games built on top of the Ethereum platform.
One well-known example of an Ethereum game is, CryptoKitties. Launched in November 2017, CryptoKitties is an Ethereum game that allows users to purchase, collect, breed and sell virtual cats.
This article will look at the top 10 Ethereum games currently running on the Ethereum blockchain, as well as metrics such as: weekly active users and weekly transaction volume.
Weekly Active Users – This metric is a measure of how many unique users interact with an Ethereum game within a certain period of time, in this case the period of time will be a week, i.e. 7 days. A unique user is defined as someone who interacts with the Ethereum game at least once in those 7 days. If they interact with the Ethereum game more than once in a week, the user will still only be counted as one active user.
Weekly Transaction Volume ($) – This metric measures the total dollar amount that was transacted over the span of a week in an Ethereum game. An example transaction could involve a player buying a virtual item from another player.
My Crypto Heroes is a HTML5 game for smartphones and PC that uses blockchain technology. It is a worker-placement, Role Playing Game (RPG) that involves collecting and training historical heroes of the world. Players can acquire special items as well as compose armies and dictate battle formations.
Weekly Active Users: 901
Weekly Transaction Volume: $39,792
As previously mentioned, CryptoKitties is an Ethereum game that allows users to purchase, collect, breed and sell virtual cats. It was the first real Ethereum game to the take the cryptocurrency space by storm with some virtual kitties reportedly being sold for over $100,000.
3. Gods Unchained
Weekly Active Users: 450
Weekly Transaction Volume: $35,254
Gods Unchained is a turn-based trading card game that is mechanically similar to Hearthstone. Players start off by building their deck from hundreds of unique cards or by buying card packs so as to stand the chance of unlocking a rare card. Built on top of the Ethereum blockchain, players are the sole owners of their cards.
Weekly Active Users: 569
Weekly Transaction Volume: $19,800
HyperDragons is a digital collectible and strategy game built on top of the Ethereum blockchain that allows players to purchase, collect, sell and trade virtual dragons, each with their own unique characteristics. The game also permits players to train their dragons for battle with other users and stand to win prizes for winning.
Weekly Active Users: 686
Weekly Transaction Volume: $14,746
Etheremon is a another Ethereum game that creates a world of Monsters (or Mons) that players can capture, train, transform, or trade. Mons can be trained to evolve or bought from the trade market. It is thought that the scarcer a Mon is, the more valuable it will be worth.
Weekly Active Users: 140
Weekly Transaction Volume: $14,176
Dragonereum is a virtual dragon collectible game whereby users can own a dragon, trade their dragons, interbreed and battle other dragons, all while collecting rewards and achievements along the way.
7. Blockchain Cuties
Weekly Active Users: 869
Weekly Transaction Volume: $8,063
Blockchain Cuties is another crypto-collectible game that allows users to accumulate and play with a range of animals including: cats, puppies, lizards and bears. Collected animals can be trained and leveled-up in order to battle other users and their collected animals.
8. Axie Infinity
Weekly Active Users: 289
Weekly Transaction Volume: $6,914
Axie Infinity is an Ethereum game based on the idea of collecting, raising and battling cute fantasy creatures called Axie. Players can create teams of Axies and battle other trainers in the Arena in order to gain experience points and level up their Axie’s stats.
9. Evolution Land
Weekly Active Users: 471
Weekly Transaction Volume: $6,371
Evolution Land is a virtual management game that allows players to buy and sell land, mine various elements and perform construction and manufacturing activities. There are different facets to the game, including: collection of different characters, educating these characters, managing any purchased land and a player vs player (PVP) element.
Weekly Active Users: 549
Weekly Transaction Volume: $4,704
0xUniverse is a crypto-collectible game that allows players to build spaceships, explore the galaxy, and to collect planets. Players can also extract resources and carry out research on their collected planets.
To conclude, the list above takes a comprehensively look at the top 10 Ethereum games currently live on the network. Key metrics that were included in the list are: weekly active users and weekly transaction volume. Judging from the numbers, the ecosystem still has a long way to go in order to encourage further use of Ethereum games. However, it is a nascent industry, and as such, suggest that there is ample room for further innovation and growth.
Blockchains are decentralized peer-to-peer systems that make use of network participants, or nodes, in order to maintain a shared ledger as to the current state of a network. The distributed nature of blockchains ensures the integrity and immutability of the ledger; consensus must be reached amongst network participants as to the current state of the blockchain.
The first use case of blockchain technology was in the creation and distribution of cryptocurrencies, with the most popular example being Bitcoin. Bitcoin makes use of the technology by maintaining a ledger of all economic transactions that takes place on its network. An example of an economic transaction would be: “Alice sends Bob 1 bitcoin”. Transactions such as these are then bundled together to form a block, which is then cryptographically linked to other blocks to form a blockchain.
The Bitcoin blockchain is what is known as a public blockchain. This means that there are no restrictions as to who can participate on the network, and in what form. For example, a participant on the Bitcoin blockchain could be in the form of a node operator, someone who is responsible for checking the validity of transactions against the network’s consensus rules. On the other hand, a participant may be a miner, someone who is responsible for appending blocks of transactions to the blockchain.
This contrasts with private
blockchains, which do restrict who network participants can be.
A private blockchain differs from a public one only in that in order to access it, participants must be invited or meet a certain set of criteria. These restrictions ensure that only specific entities can be granted access.
One example use case of private blockchains include: the execution and recording of transactions between large financial institutions. In this context, banks could use blockchain technology to form a distributed network and transact amongst each other. This offers the advantage of a more seamless trading experience, as typically, banks have differing technologies which must communicate in order for a transaction to be successfully executed. In this scenario, access to the private blockchain is limited only to banks; there would exist a protocol on the network for admitting new banks as well as coming to consensus as to the current state of the network. In addition, private blockchains preserve the privacy of its participants and their activities, and so, is the natural choice for institutions who value privacy.
Other uses cases of private blockchains include:
Vote counting – governments could utilise this technology during democratic processes.
Digital identity – governments and corporations could use private blockchains to store the digital identities of citizens and employees.
Asset ownership – institutions may use a blockchain to track the ownership of financial assets such as stocks and bonds.
Supply chain management – corporations may use blockchains to track goods in its supply chain.
Aside from their potential use cases, there do exist real-life examples of private blockchains.
Hyperledger Fabric is an open source blockchain implementation framework that uses smart contract technology and is hosted by The Linux Foundation.
Corda is a private blockchain project developed by the company, R3. Corda allows companies to build blockchain networks that can facilitate for direct business-to-business transactional and smart contract privacy.
To conclude, private blockchains are decentralized peer-to-peer networks that rely on network participants to come to consensus on the current state of the network. Participants must be invited or meet a certain set of criteria in order to be granted access.
Example use cases of private blockchains include: monitoring and executing transactions, vote counting and supply chain management.
Private blockchain projects currently in development include: Corda and Hyperledger Fabric.