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Ethereum Account Nonce

Seth Cli Sawtooth V0.8.13 Documentation

Seth Cli Sawtooth V0.8.13 Documentation

The seth command can be used to interact with the Sethtransaction family. It provides functionality for loading and executing smartcontracts, querying the data associated with a contract, and generating keys inthe format used by the tool. The following section reproduces the CLI usageoutput obtained by running seth and its various subcommands with the See the final section for an explanation of how to generate contractinitialization data and how to format function calls using the EthereumContract ABI. Usage: seth [OPTIONS] Application Options: -v, --verbose Set the log levelHelp Options: -h, --help Show this help messageAvailable commands: account Manage seth accounts contract Deploy and execute contracts init Initialize seth to communicate with the given URL permissions Manage permissions of accounts show Show data associated with accounts and transactions Usage: seth [OPTIONS] init [url]Application Options: -v, --verbose Set the log levelHelp Options: -h, --help Show this help message Usage: seth [OPTIONS] show Application Options: -v, --verbose Set the log levelHelp Options: -h, --help Show this help messageAvailable commands: account Show all data associated with a given account events Show events associated with a given transaction ID receipt Show receipt associated with a given transaction ID Usage: seth [OPTIONS] account Application Options: -v, --verbose Set the log levelHelp Options: -h, --help Show this help messageAvailable commands: create Create a new externally owned account import Import the private and create an alias for later reference list List all imported accounts as "alias: address" Usage: seth [OPTIONS] account import [import-OPTIONS] [key-file] [alias]Application Options: -v, --verbose Set the log levelHelp Optio 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 >>

Frequently Asked Questions

Frequently Asked Questions

How long should it take to download the blockchain? The Ethereum blockchain is constantly growing, and is nearing 10GB as of March 2016. The amount of time it will take to download depends on the amount of peers you are able to connect to, your internet connection speed, and other factors. See the download-the-blockchain-faster section for tips on syncing the blockchain more quickly. How do I get a list of transactions into/out of an address? You would have to pull the transactions manually out of the blockchain to achieve this. Alternatively, you can rely on third party explorers APIs like Etherchain . For contract execution transactions however, you can filter the contract logs to achieve this. Can a transaction be sent by a third party? i.e can transaction broadcasting be outsourced Technically yes, but there is an important restriction as opposed to bitcoin signed transactions: in ethereum the transaction has a nonce (more precisely, each account increases a counter when sending a transaction based on how many transactions total have been sent. If 3 transactions have ever been sent from the account, the account nonce would be 3). Can Ethereum contracts pull data using third-party APIs? No, Ethereum contracts cannot pull data from external information sources in this way. It is however possible to push data from external sites (e.g. weather sites, stock prices) to Ethereum contracts through transactions. There are oracle services that are compatible with the Ethereum network that will pull/push data to the Ethereum network for a fee. Is the content of the data and contracts sent over the Ethereum network encrypted? Data and contracts on the Ethereum network are encoded, but not encrypted. Everyone can audit the behavior of the contracts and the data sent to them. Ho Continue reading >>

Ethereum Quirks And Vulns

Ethereum Quirks And Vulns

Ive continued diving deep into the mechanics of Ethereum, previously finding vulnerabilities in python client and the Go and C++ clients as well as insecure contracts . Lately, Ive come across a few interesting quirks as well as some more vulnerabilities. There are two types of accounts within Ethereum; normal accounts and contract accounts. Contracts are created by sending transactions with empty to-fields, and contain some data which is executed (ala constructor) and, hopefully, returns some code which gets placed on the blockchain. The contracts are, naturally, part of the same address space as the normal accounts; and the address of a contract is determined thus : address = sha3(rlp_encode(creator_account, creator_account_nonce))[12:] This is fully deterministic; for a given account, say, accountA is 0x6ac7ea33f8831ea9dcc53393aaa88b25a785dbf0, the addresses that it will create are the following: nonce0= "0xcd234a471b72ba2f1ccf0a70fcaba648a5eecd8d"nonce1= "0x343c43a37d37dff08ae8c4a11544c718abb4fcf8"nonce2= "0xf778b86fa74e846c4f0a1fbd1335fe81c00a0c91"nonce3= "0xfffd933a0bc612844eaf0c6fe3e5b8e9b6c1d19c" This is a bit interesting; it means that these can be used to hide money. From accountA, we can send ether to e.g. the nonce1-address. At this address, the ether will be unrecoverable, until we first make a transaction (increasing accountA nonce to 1) and then create a contract which lands on nonce1 and thus becomes the owner of the money; and can send it back again. Furthermore, it would be possible to not just hide money in vertical mode via nonce, but also horizontally by deeper levels of contracts: nonce+3 --> contract3 nonce+2 nonce+1 nonce+2 --> contract1 --> contract2 : nonce nonce+1`accountA` : nonce The operation above could be expressed as up,up, in, in, up,u Continue reading >>

Ethereum - Blockcypher Account Nonce Too Far Behind Transaction - Stack Overflow

Ethereum - Blockcypher Account Nonce Too Far Behind Transaction - Stack Overflow

BlockCypher Account nonce too far behind transaction I'm currently working on a DApp that involves sending transactions. I'm using BlockCypher to send the transactions since the API is fairly straight forward. One issue I'm finding is that when I run my API locally and call the send transaction method I receive the transaction hash and I'm able to check it on Etherscan and the transaction does goes ahead. The next step of course is deploying the API and then testing it, when I do this and hit the API endpoint with the exact same parameters. I receive the following error: Error validating transaction: Account nonce 68 too far behind transaction 0xad50ba948fc3fe266fb19c4aa3f3a81928ff114b3fadf597a620ec86eada7cf0:. It doesn't appear that the transaction in question even exists (from searching for it on Etherscan) and so it seems that my Nonce for this account is out of sync with what it should be. Is that even possible? And what is the way to overcome this issue? As it turns out, what I've found out is that the account should have a nonce of over 200. Here is how I construct the transaction: var count = web3.eth.getTransactionCount(FROM_ADDR); //console.log(count); //Does actually return over 200 both locally and on the server. var data = myContractInstance.transfer.getData(to, value, { from: FROM_ADDR }); var gasPrice = "2000000000"; var gasLimit = 90000; var rawTransaction = { "from": FROM_ADDR, "nonce": web3.toHex(count), "gasPrice": web3.toHex(gasPrice), "gasLimit": web3.toHex(gasLimit), "to": to, "data": data, "chainId": 0x01 }; console.log(rawTransaction); //The nonce is still over 200 (Though in hex obviously). Strangely, when I changed the address the transactions are correctly sending again on both my local machine and the server. I've left a email for BlockCypher 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 >>

Cancel Pending Transactions On Ethereum

Cancel Pending Transactions On Ethereum

Oct 9, 2017 00:23 695 words 4 minutes read ethereum pending transaction geth Ethereum transactions model is vastly different from Bitcoin. Instead of using UTXO (unspent transaction outputs)transaction uniqueness and order are achieved using transaction nonce. It is an integer (uint256) counter whichis incremented for each transaction of an account. Its value is effectively the number of transactions sent from a given address andits value must be included in every transaction. transactions must be processed in order (transaction with a nonce of 1 must be processed before the transaction with a nonce of 2) no skipping (transaction with a nonce of 4 cannot be included in a block until transactions with nonces of 1, 2, 3 are processed) This way the network is able to identify duplicates of transactions and enforce their order (which is essential for smart contracts). Each transaction must set gas price which directly affects transaction fees.Miners optimize their profits by including transactions with a high gas price first. If gas price is low the transaction will wait for a long time until it is mined.Eventually, it will be mined (sometimes many hours later) or dropped (miners have limited resources to queue pending transactions).However, even if the transaction is dropped by miners it may still await in pendingTransaction list of your client and artificially increaseyour nonce. You can explore the list of pending transactions on Etherscan . When a transaction is waiting for being mined all subsequent transactions are blocked. They cannot be included in a blockuntil the previous one is included (it is determined by mentioned nonce value). Even if subsequent transactions havea very high gas price they cannot be processed as it would break the order of transactions and pr 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 >>

Eth Gas Station Metropolis Release: Pending Tx Reports, A Smarter Calculator, And The Nonce-filtered Rig View Of The Txpool

Eth Gas Station Metropolis Release: Pending Tx Reports, A Smarter Calculator, And The Nonce-filtered Rig View Of The Txpool

ETH Gas Station Metropolis Release: Pending Tx Reports, a smarter calculator, and the Nonce-Filtered Rig View of the Txpool ETH Gas Station Metropolis Release: Pending Tx Reports, a smarter calculator, and the Nonce-Filtered Rig View of the Txpool ETH Gas Station Metropolis Release: Pending Tx Reports, a smarter calculator, and the Nonce-Filtered Rig View of the Txpool As I write this, Ethereum transaction dynamics have never looked so healthy. Gas prices have fallen about 20x compared to several months ago and at the same time confirmation times have improved dramatically. Transactions are now confirmed so quickly and cheaply, fair to ask who needs calculators? Nevertheless, in the spirit of mainstream adoption, there are a few new transaction pool / gas price tools that I think may still be useful. The following sequence remains a not uncommon situation: User sends a very low gas price / high gas transaction. It does not confirm. User gets tired of waiting and then sends a new transaction with a normal gas price from the same account. It still does not confirm. User then suspects that Ethereum is screwed up. This, in a nutshell, is the somewhat confusing reality of the Ethereum account nonce system- all transactions from the same account must be mined in sequence. If you send a transaction that miners dont like, sending a new transaction from the same account wont get mined until the offending one is mined first. It turns out that this conditional acceptance of transactions, when there are multiple transactions from the same account pending in the Txpool, is very important for understanding Txpool dynamics. In fact, whereas there are often a couple of thousand transactions pending in the Txpool at any given time, a large majority of them are often from a small number Continue reading >>

Node.js - Testrpc: The Tx Doesn't Have The Correct Nonce - Stack Overflow

Node.js - Testrpc: The Tx Doesn't Have The Correct Nonce - Stack Overflow

Testrpc: the tx doesn't have the correct nonce I have been experimenting with truffle recently and followed the following tutorial: Whenever I try to setup a transaction I keep getting the same error below Error: Error: the tx doesn't have the correct nonce. account has nonce of: 14 tx has nonce of: 0 Checked online and read up on a lot of articles related to this but so far haven't found what might be causing this issue. From what I understand it seems it is unable to find the previous transactions to hash the new transaction? Try to reconnect to your TestRPC network in MetaMask: Select Main Ethereum Network (or any other than Localhost 8545) Exactly same for me. I too restarted TestRPC. matrix Dec 31 '17 at 19:21 That doesn't always work for me, but when I do that + reset the account it always works. Teleporting Goat Mar 7 at 9:58 Using MetaMask v3.14.1 you can reset your account as follow: Resetting an Account In the Settings menu, MetaMask has a "Reset Account" button. This button wipes the current account's transaction history, which is used to calculate the current account nonce. Normal users should never have a reason to use this feature. This is useful for developers who reset a test network but want to continue using the same account, forcing MetaMask to believe this network ID is a clean network in a fresh state. Old response:Answer of yatskevich is correct. However, for people how are using Truffle 4+ with "truffle develop", you need to remove and reinstall MetaMask to get it work again, every time you run Truffle Develop! This issue is addressed here: , here: , and also here: In short they are working on it and in the mean time you need to reinstall MetaMask every time! Continue reading >>

Transactions Web3j 3.3.1 Documentation

Transactions Web3j 3.3.1 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 >>

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 >>

Bitcoin Litecoin E Dogecoin - Ethereum Account Nonce, Bitcointalk Tenx Pay, Bitcoin Gold Price Outlook

Bitcoin Litecoin E Dogecoin - Ethereum Account Nonce, Bitcointalk Tenx Pay, Bitcoin Gold Price Outlook

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Creating Offline Ethereum Transactions In Javascript

Creating Offline Ethereum Transactions In Javascript

Creating offline Ethereum transactions in JavaScript By Mikko Ohtamaa a year ago. Tagged under ethereum , javascript , web3 , etherscan . In this blog post we show how to create Ethereum blockchain transactions programmatically in JavaScript and offline. This is the second part of tutorial blog posts continuing the earlier Ethereum JavaScript tutorial left. We bend the meaning of the word offline here a bit. We still communicate with Ethereum network to get the gas cost and the next transaction nonce. However, the private key never leaves the computer. This blog post serves mostly as an example. Advanced users can use the script presented here for doing Ether cold wallet and offline transactions. Target address, either a contract or an Ethereum account. Nonce, incremented once per transaction per account, to prevent double spend attacks. Value, how many Ethers are transferred. Can be 0 for contract calls, but you still need to pay for the gas. The maximum gas the transaction is allowed pull from the sending account. The gas price if the transaction needs a preferential treatment. Optional data payload that would include any function call and arguments encoded. Transaction is signed with the private key of the sending account address. Based on these arguments you can create a raw transaction, as a hex string, that can be pushed to the network. Pushing can happen either through EtherScan.io service or through web3.eth.sendRawTransaction API. Furthermore in this particular example we also need EtherScan.io API key - we use their API to communicate with the network The example script is available on TokenMarket Github repository . Install dependencies with NPM - see previous blog post Please note that this command line monster will go away in the future when Node.js starts Continue reading >>

Transactions - What Is Nonce In Ethereum? How Does It Prevent Double Spending? - Ethereum Stack Exchange

Transactions - What Is Nonce In Ethereum? How Does It Prevent Double Spending? - Ethereum Stack Exchange

What is nonce in Ethereum? How does it prevent double spending? recently I got fascinated by blockchain, and started learning Ethereum. I came across Concept of the nonce in Ethereum. After researching I found out that nonce is used for two purposes a. To keep transaction related to an account in order. i.e if there is a transaction with nonce 3 related to some account in the txpool and some transaction will nonce 4 arrived then that transaction won't be mined until and unless transaction with nonce 3 is mined. But I have some question that I am not able to find? i) nonce value is related to an address, right? So two address can have same nonce at the same time i.e. account with Address A can have the latest nonce 2 similarly account with address B can also have latest nonce 2. ii) Do all nodes in the network will have same latest nonce value for all accounts available in the network? That is, if there are three accounts and 2 miners then and nonce value for three accounts are 1,2,3 respectively, then both miner will have the same nonce. b) how is nonce used to prevent a double spend? If you refer the Glossary at Github Wiki , there are two types of nonce used in Ethereum. Account nonce - It's simply the transaction count of an account Proof of work nonce - The random value in a block that was used get the proof of work satisfied (depending on the difficulty at the time). Here you are referring to the account nonce, which is the transaction count from that account. i)Nounce value is related to an address right?So two address can have same nounce at the same time i.e account with Address A can have latest nounce 2 similarly account with address B can also have latest nounce 2. Yes as explained above, it's the transaction count and hence it's related to the account. And Continue reading >>

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