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Ethereum Mining Nonce

Transactions Web3j 3.1.1 Documentation

Transactions Web3j 3.1.1 Documentation

Mining it yourself in a private environment, or the public test environment (testnet) is verystraight forwards. However, in the main live environment (mainnet) it requires significantdedicated GPU time which is not likely to be feasible unless you already have a gaming PC withmultiple dedicated GPUs. If you wish to use a private environment, there is some guidance on the Homestead documentation . To purchase Ether you will need to go via an exchange. As different regions have differentexchanges, you will need to research the best location for this yourself. The Homestead documentation contains a number of exchanges which is a good place to start. There are a number of dedicated test networks in Ethereum, which are supported by various clients. For development, its recommended you use the Rinkeby or Kovan test networks. This is because theyuse a Proof of Authority (PoA) consensus mechanism, ensuring transactions and blocks are created ina consistent and timely manner. The Ropsten testnet, although closest to the Mainnet as it usesProof of Work (PoW) consensus, has been subject to attacks in the past and tends to be moreproblematic for developers. You can request Ether for the Rinkeby testnet via the Rinkeby Crypto Faucet, available at . Details of how to request Ether for the Kovan testnet are available here . If you need some Ether on the Ropsten testnet to get started, please post a message with yourwallet address to the web3j Gitter channel and you will besent some. In the Ethereum test environment (testnet), the mining difficulty is set lower then the mainenvironment (mainnet). This means that you can mine new Ether with a regular CPU, such as yourlaptop. What youll need to do is run an Ethereum client such as Geth or Parity to start buildingup reserves. Further ins Continue reading >>

Explaining The Genesis Block In Ethereum

Explaining The Genesis Block In Ethereum

Every blockchain has to start somewhere, so theres whats called a genesis block at the beginning. This is the first block, and in it the creators of Ethereum were at liberty to say To start, the following accounts all have X units of my cryptocurrency. Any transfer of that ether on the blockchain will have originated from one of these initial accounts (or from mining). Every time we launch Ethereum, we actually recreate this genesis block from scratch. Syncing the blockchain with peers only begins at block 1. The genesis block is created using the genesis state file or genesis.json in Geth. This file contains all the data that will be needed to generate block 0, including who starts out with how much ether. Heres an example of a custom genesis state file that initializes this block. // genesis.json{ "alloc": { "0xca843569e3427144cead5e4d5999a3d0ccf92b8e": { "balance": "1000000000000000000000000000" }, "0x0fbdc686b912d7722dc86510934589e0aaf3b55a": { "balance": "1000000000000000000000000000" } }, "config": { "chainID": 68, "homesteadBlock": 0, "eip155Block": 0, "eip158Block": 0 }, "nonce": "0x0000000000000000", "difficulty": "0x0400", "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000", "coinbase": "0x0000000000000000000000000000000000000000", "timestamp": "0x00", "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000", "extraData": "0x43a3dfdb4j343b428c638c19837004b5ed33adb3db69cbdb7a38e1e50b1b82fa", "gasLimit": "0xffffffff"} Lets break down some of the fields in the genesis state file. If you find this post useful, I encourage you to follow my Twitter account, where I post more tutorials and low-level explanations. The config struct in genesis.json has to do with setting configuration variables for Ethereum, and ha Continue reading >>

How Ethereum Mining Works

How Ethereum Mining Works

Today, miners play an important role in making sure ethereum works. This role isn't immediately obvious, though. Many new users think that the sole purpose of mining is to generate ethers in a way that doesn't require a central issuer (seeour guide" What is Ether? "). This is true. Ethereum's tokens are created through the process of mining at a rate of 5 ether per mined block. But mining also has another at least asimportant role. Usually, banks are in charge of keeping accurate records of transactions. They ensure that money isn't created out of thin air, and that users don't cheat and spend their money more than once. Blockchains, though, introduce an entirely new way of record-keeping, one where the entire network, rather than an intermediary, verifies transactions and adds them to the public ledger. Although a 'trustless' or 'trust-minimizing' monetary system is the goal, someone still needs to securethe financial records, ensuring that no one cheats. Mining is one innovation that makes decentralized record-keeping possible. Miners come to consensus about the transaction history while preventing fraud (notably the double spending of ethers) an interesting problem that hadnt been solved in decentralized currencies before proof-of-work blockchains. Although ethereum is looking into other methods of coming to consensus about the validity of transactions, mining currently holds the platform together. Today, ethereum's mining process is almost the same as bitcoins . For each block of transactions, miners use computers to repeatedly and very quickly guess answers to a puzzle until one of them wins. More specifically, the miners will run the blocks unique header metadata (including timestamp and software version) through a hash function (which will return a fixed-length, Continue reading >>

Mining Ethereum/wiki Wiki Github

Mining Ethereum/wiki Wiki Github

The word mining originates in the context of the gold analogy for crypto currencies. Gold or precious metals are scarce, so are digital tokens, and the only way to increase the total volume is through mining it. This is appropriate to the extent that in Ethereum too, the only mode of issuance post launch is via the mining. Unlike these examples however, mining is also the way to secure the network by creating, verifying, publishing and propagating blocks in the blockchain. Mining Ether = Securing the network = verify computation Ethereum Frontier like all blockchain technologies uses an incentive-driven model of security. Consensus is based on choosing the block with the highest total difficulty.Miners produce blocks which the others check for validity. Among other well-formedness criteria, a block is only valid if it contains proof of work (PoW) of a given difficulty.Note that in Ethereum 1.1, this is likely going to be replaced by a proof of stake model. The proof of work algorithm used is called Ethash (a modified version of Dagger-Hashimoto ) involves finding a nonce input to the algorithm so that the result is below a certain threshold depending on the difficulty. The point in PoW algorithms is that there is no better strategy to find such a nonce than enumerating the possibilities while verification of a solution is trivial and cheap. If outputs have a uniform distribution, then we can guarantee that on average the time needed to find a nonce depends on the difficulty threshold, making it possible to control the time of finding a new block just by manipulating difficulty. The difficulty dynamically adjusts so that on average one block is produced by the entire network every 12 seconds (ie., 12 s block time). This heartbeat basically punctuates the synchronisation Continue reading >>

Cryptographic Nonce - Wikipedia

Cryptographic Nonce - Wikipedia

This article needs additional citations for verification . Relevant discussion may be found on the talk page . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed. ( Learn how and when to remove this template message ) Typical clientserver communication during a nonce-based authentication process including both a server nonce and a client nonce. In cryptography , a nonce is an arbitrary number that can only be used once. It is similar in spirit to a nonce word , hence the name. It is often a random or pseudo-random number issued in an authentication protocol to ensure that old communications cannot be reused in replay attacks . They can also be useful as initialization vectors and in cryptographic hash functions . A nonce is an arbitrary number used only once in a cryptographic communication, in the spirit of a nonce word . They are often random or pseudo-random numbers. Many nonces also include a timestamp to ensure exact timeliness, though this requires clock synchronization between organizations. The addition of a client nonce ("cnonce") helps to improve the security in some ways as implemented in digest access authentication . To ensure that a nonce is used only once, it should be time-variant (including a suitably fine-grained timestamp in its value), or generated with enough random bits to ensure a probabilistically insignificant chance of repeating a previously generated value. Some authors define pseudo-randomness (or unpredictability) as a requirement for a nonce. [1] Authentication protocols may use nonces to ensure that old communications cannot be reused in replay attacks . For instance, nonces are used in HTTP digest access authentication to calculate an MD5 digest of the password . Th Continue reading >>

Mining Ethereum Homestead 0.1 Documentation

Mining Ethereum Homestead 0.1 Documentation

Mining success depends on the set block difficulty. Block difficulty dynamically adjusts each block in order to regulate the network hashing power to produce a 12 second blocktime. Your chances of finding a block therefore follows from your hashrate relative to difficulty. Ethash uses a DAG (directed acyclic graph) for the proof of work algorithm, this is generated for each epoch, i.e., every 30000 blocks (125 hours, ca. 5.2 days). The DAG takes a long time to generate. If clients only generate it on demand, you may see a long wait at each epoch transition before the first block of the new epoch is found. However, the DAG only depends on the block number, so it can and should be calculated in advance to avoid long wait times at each epoch transition. Both geth and ethminer implement automatic DAG generation and maintains two DAGs at a time for smooth epoch transitions. Automatic DAG generation is turned on and off when mining is controlled from the console. It is also turned on by default if geth is launched with the --mine option. Note that clients share a DAG resource, so if you are running multiple instances of any client, make sure automatic dag generation is switched off in all but one instance. To generate the DAG for an arbitrary epoch: For instance geth makedag 360000 ~/.ethash. Note that ethash uses~/.ethash (Mac/Linux) or ~/AppData/Ethash (Windows) for the DAGso that it can shared between different client implementations as well as multiple running instances. Our algorithm, Ethash (previously known as Dagger-Hashimoto), is based around the provision of a large, transient, randomly generated dataset which forms a DAG (the Dagger-part), and attempting to solve a particular constraint on it, partly determined through a blocks header-hash. It is designed to hash Continue reading >>

Making Sense Of Ethereum Nonce(sense)

Making Sense Of Ethereum Nonce(sense)

Experienced Software Engineer. Senior Android Engineer @ Kik We expect users to send multiple Kin transactions in a row. Were not expecting users to understand blockchain and monitor their transactions manually. When testing our Kin wallet SDK ( Android and iOS ), we witnessed a problem sending multiple transactions one after the other. In a specific period of time, all of our transactions got stuck we couldnt see that they were pending, and eventually they were cancelled. As it turns out, transactions had the same nonce for multiple transactions. Proof of work nonce: A meaningless value in a block that can be adjusted in order to try to satisfy the proof of work condition. This is the essence of mining. This value makes satisfying proof of work hard computational work that depends on luck. Account nonce: A transaction counter in each account that prevents replay attacks . For example, a transaction sending 20 coins from A to B can be repeated over and over by B to continually drain As balance. Our problem is related to the latter nonce the transaction counter. When making a transaction in Ethereum, a consecutive number should be attached to each transaction on the same account. Each node will process transactions from a specific account in a strict order according to the value of its nonce. Therefore, failing to increment this value correctly can result in different kinds of errors. For instance, lets say the latest transaction nonce was 121: Reusing nonce: if we send a new transaction for the same account with a nonce of either 121 or below, the node will reject it. Gaps: if we send a new transaction with a nonce of either 123 or higher, the transaction will not be processed until this gap is closed, i.e. until a transaction with nonce 122 has been processed. As ment Continue reading >>

Glossary Ethereum/wiki Wiki Github

Glossary Ethereum/wiki Wiki Github

See also: Computational infeasibility: a process is computationally infeasible if it would take an impracticably long time (eg. billions of years) to do it for anyone who might conceivably have an interest in carrying it out. Generally, 280 computational steps is considered the lower bound for computational infeasibility. Hash: a hash function (or hash algorithm) is a process by which a piece of data of arbitrary size (could be anything; a piece of text, a picture, or even a list of other hashes) is processed into a small piece of data (usually 32 bytes) which looks completely random, and from which no meaningful data can be recovered about the document, but which has the important property that the result of hashing one particular document is always the same. Additionally, it is crucially important that it is computationally infeasible to find two documents that have the same hash. Generally, changing even one letter in a document will completely randomize the hash; for example, the SHA3 hash of "Saturday" is c38bbc8e93c09f6ed3fe39b5135da91ad1a99d397ef16948606cdcbd14929f9d, whereas the SHA3 hash of Caturday is b4013c0eed56d5a0b448b02ec1d10dd18c1b3832068fbbdc65b98fa9b14b6dbf. Hashes are usually used as a way of creating a globally agreed-upon identifier for a particular document that cannot be forged. Encryption: encryption is a process by which a document (plaintext) is combined with a shorter string of data, called a key (eg. c85ef7d79691fe79573b1a7064c19c1a9819ebdbd1faaab1a8ec92344438aaf4), to produce an output (ciphertext) which can be "decrypted" back into the original plaintext by someone else who has the key, but which is incomprehensible and computationally infeasible to decrypt for anyone who does not have the key. Public key encryption: a special kind of encr Continue reading >>

Nonce Definition | Investopedia

Nonce Definition | Investopedia

The blockchain is the cornerstone of cryptocurrency . In order to keep the blockchain secure, data from previous blocks are encrypted or hashed into a series of numbers and letters. This is done by processing the block input through a function, which produces an output of a fixed length. The function used to generate the hash is deterministic, meaning that it will produce the same result each time the same input is used; can generate a hashed input efficiently; makes determining the input difficult (leading to mining ); and makes small changes to the input result in a very different hash. Adding transactions to the blockchain requires substantial computer processing power. The individuals and companies who process blocks are called miners. Miners are compensated only if they are the first to create a hash that meets a certain set of requirements, called the target hash . The process of guessing the hash starts in the block header. It contains the block version number, a timestamp, the hash used in the previous block, the hash of the Merkle Root, the nonce, and the target hash. Successfully mining a block requires a miner to be the first to guess the nonce, which is a random string of numbers. This number is appended to the hashed contents of the block, and then rehashed. If the hash meets the requirements set forth in the target, then the block is added to the blockchain. Cycling through solutions in order to guess the nonce is referred to as proof of work , and the miner who is able to find the value is awarded the block and paid in cryptocurrency. Determining which string to use as the nonce requires significant amount of trial-and-error, as it is a random string. A miner must guess a nonce, append it to the hash of the current header, rehash the value, and compare t Continue reading >>

Neat Ethereum Tricks. The Transaction Nonce.

Neat Ethereum Tricks. The Transaction Nonce.

Neat Ethereum tricks. The transaction nonce. Neat Ethereum tricks. The transaction nonce. Whenever a user deploys a new contract to the Ethereum blockchain, that contract receives its own Ethereum address. User 0x0a Deploying contract Reclaim > contract address 0x0a1 As it turns out, these contract addresses ARE NOT a random address. The address of every contract well deploy depends on two parameters: The Ethereum address from which the contract is being deployed. The nonce of the transaction! Not to be confused with the nonce used in the mining process. In Ethereum, every transaction have a nonce associated with it. The nonce is one of the tools that helps to index and process transactions in the right order. The nonce itself IS NOT a random value. It grows by scalar one with every transaction we transmit to the blockchain. For the Ethereum test-net, the nonce begins with 0x100000 (1048576). The new contract address can be computed in the following way: def mk_contract_address(sender, nonce): return sha3(rlp.encode([normalize_address(sender), nonce]))[12:] sha3 and rlp and encryption functions. The only two variables are the address of the sender and the nonce (basically the transaction number for that particular address). Ive installed the pyethereum library on ubuntu 16.04. and changed dir to directory cd /pyethereum/ethereum . There I launched python 2.7.12 and imported the utils. $ cd/pyethereum/ethereum$ python>> import utils Than I used the functionutils.mk_contract_address(sender address, nonce) to get the addresses of my future contracts. For the sender address: 0x43CCFE27708381164Fd079556C7Ef158A6d409DcI can check for what the address of the next deployed contract will be. nonce1 =1048576 =>; 0x7930935a32ee489bd102002c2598602ff79c24fdnonce2 =1048577 =>; 0x0d7 Continue reading >>

Ethereum Mining Guide: 2018 Edition

Ethereum Mining Guide: 2018 Edition

The following article was originally published on Reliablecoins website . Mining Ethereum is sorting through data blocks from peer distributed cryptocurrency networks to find information that can be used to solve challenging math problems. Successful Ethereum miners can earn crypotocurrency in in exchange for their work. Ethereum mining requires a lot of intensive computation work, time and lots of processing power. Ethereum is a platform with several applications that are helpful for users trying to do a variety of everyday tasks very simply. Results generated through digital mining is referred to as proof of work system. The process of getting cryptocurrency tokens of Ethereum from blockchain networks requires having computers programmed to run a hashing algorithm non-stop. The hashing algorithm condenses a large amount of information into fixed length string of numbers and letters. Ethash, the hashing algorithm employed by Ethereum, hashes metadata drawn from the most recently available using a nonce. This binary number is able to create a unique hash value. With every new block contained in the blockchain, a new target hash value is set by the network. All miners on that network attempt to guess which nonce will result in the desired value. The miner that discovers the right nonce is awarded the block and receives 5 ether. The process begins again following a cycle which occurs about every 12 seconds. Ethereum Mining Rigs:Dedicated machines can mine ethereum much faster than average computers, but youll need a little bit of help building an efficient mining workhorse like this one. For people interested in doing this type of mining, it is important to get an Ethereum mining how to guide that will walk through every possible step, explain the process in detail and m Continue reading >>

Ethereum's Memory Hardness Explained, And The Road To Mining It With Custom Hardware

Ethereum's Memory Hardness Explained, And The Road To Mining It With Custom Hardware

Ethereum's Memory Hardness Explained, and the Road to Mining It with Custom Hardware Ethereum's Memory Hardness Explained, and the Road to Mining It with Custom Hardware As crypto-currencies increase in value, so does the payout from mining them. This creates a substantial economic incentive to not only deploy more mining hardware, but to also develop faster, more efficient mining hardware. We saw this with bitcoin: Mining migrated from CPUs, to GPUs, to FPGAs, and now to ASICs [1] . Today, Ethereum GPU mining is the norm, but the miners havent made the jump to running the ethereum mining/hashing algorithm, ethash, on specialized hardware solutions (e.g. FPGAs and ASICs). Plenty of articles and forums attribute this to ethash being memory hard (a.k.a. memory bound ). Here, Ill walk through where Ethereum minings memory hardness comes from, and what the next generation of custom ethereum mining hardware might look like. For this article, Im assuming readers have a general understanding of standard computer technologies and crypto-currency blockchains, but dont need to be programming or mining experts. For a more technical, programmer-oriented explanation of Ethereums mining algorithm, called ethash, please refer to the ethash page on the ethereum wiki . For a less technical introduction to blockchains, visit the blockgeeks blockchain guide here . In proof-of-work mining, miners are tasked with generating a short binary blob (called a nonce), which, when hashed, produces an output value less than a pre-specified target threshold. Due to the cryptographic nature of each currencys hash function, there is no way to reverse-engineer or back-compute a nonce that satisfies the target threshold limit. Instead, miners must guess-and-check hashes as fast as possible, and hope the Continue reading >>

Introduction | Ethereum Frontier Guide

Introduction | Ethereum Frontier Guide

The word mining originates in the context of the gold analogy for crypto currencies. Gold or precious metals are scarce, so are digital tokens, and the only way to increase the total volume is through mining it. This is appropriate to the extent that in Ethereum too, the only mode of issuance post launch is via the mining. Unlike these examples however, mining is also the way to secure the network by creating, verifying, publishing and propagating blocks in the blockchain. Mining Ether = Securing the network = verify computation Ethereum Frontier like all blockchain technologies uses an incentive-driven model of security. Consensus is based on choosing the block with the highest total difficulty. Miners produce blocks which the others check for validity. Among other well-formedness criteria, a block is only valid if it contains proof of work (PoW) of a given difficulty. Note that in Ethereum 1.1, this is likely gonna be replaced by a proof of stake model. [The proof of work algorithm used is called Ethash (a modified version of Dagger-Hashimoto involves finding a nonce input to the algorithm so that the result is below a certain threshold depending on the difficulty. The point in PoW algorithms is that there is no better strategy to find such a nonce than enumerating the possibilities while verification of a solution is trivial and cheap. If outputs have a uniform distribution, then we can guarantee that on average the time needed to find a nonce depends on the difficulty threshold, making it possible to control the time of finding a new block just by manipulating difficulty. The difficulty dynamically adjusts so that on average one block is produced by the entire network every 12 seconds (ie., 12 s block time). This heartbeat basically punctuates the synchronisation o Continue reading >>

The Question Of Mining

The Question Of Mining

There are a lot of interesting changes to the Ethereum protocol that are in the works, which will hopefully improve the power of the system, add further features such as light-client friendliness and a higher degree of extensibility, and make Ethereum contracts easier to code. Theoretically, none of these changes are necessary; the Ethereum protocol is fine as it stands today, and can theoretically be released as is once the clients are further built up somewhat; rather, the changes are there to make Ethereum better. However, there is one design objective of Ethereum where the light at the end of the tunnel is a bit further: mining decentralization. Although we always have the backup option of simply sticking with Dagger, Slasher or SHA3, it is entirely unclear that any of those algorithms can truly remain decentralized and mining pool and ASIC-resistant in the long term (Slasher is guaranteed to be decentralized because its proof of stake, but has its own moderately problematic flaws). The basic idea behind the mining algorithm that we want to use is essentially in place; however, as in many cases, the devil is in the details. This version of the Ethereum mining algorithm is a Hashcash-based implementation, similar to Bitcoins SHA256 and Litecoins scrypt; the idea is for the miner to repeatedly compute a pseudorandom function on a block and a nonce, trying a different nonce each time, until eventually some nonce produces a result which starts with a large number of zeroes. The only room to innovate in this kind of implementation is changing the function; in Ethereums case, the rough outline of the function, taking the blockchain state (defined as the header, the current state tree, and all the data of the last 16 blocks), is as follows: Let h[i] = sha3(sha3(block_head Continue reading >>

What You Should Know About Nonces And Difficulty

What You Should Know About Nonces And Difficulty

Verify is a Reputation Protocol for the blockchain What you should know about nonces and difficulty This is the sixth in a series of posts where we discuss the core concepts behind the Blockchain, Bitcoin and Ethereum. At Verify, were building a reputation protocol on the Ethereum blockchain and are sharing these posts in an effort to share our knowledge with the wider crypto community. In Ethereum ABC , we introduced the accounts fields. We mentioned the nonce field, but never explained it. This post will dive into that. Every transaction in Ethereum has what is called a nonce. We first saw the word nonce in our talk about Bitcoins mining , used to find proof of work; is it the same nonce in Ethereum transactions? Let us look into this question. In Ethereum there is a nonce for the block, which is similar to what we have been introduced to in Bitcoin. There is also a nonce for every transaction (in external accounts). It is the number of transactions made or sent from a given address. Whenever you send a transaction the nonce is incremented by one. The reason for a nonce in a transaction is to ensure: > That transactions are executed in order. You may have already guessed why this is important. Well, you guessed right: it is to prevent double-spends. Consider an example where: you send out a transaction with normal GASPRICE, when it is waiting to be added by some miner you send out another transaction with high GASPRICE to have the second mined before the first, making the first transaction invalid. That is why you have a nonce in Ethereum transactions, double-spends can never happen. A transaction of nonce 2 can never be mined before a transaction of nonce 1. Also note that a nonce cant be skipped. Meaning if you sent out a transaction with nonce 3 without sending no Continue reading >>

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