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Merkle Ethereum

Merkle Tree Necessity Or Atavism? Credits Medium

Merkle Tree Necessity Or Atavism? Credits Medium

CREDITS is an open blockchain platform with smart contracts and an internal cryptocurrency. #fintech #ico Data structure called Merkle tree allowing to implement address mapping and accounts creation in the Ethereum system is one the most crucial elements which maintains functioning and security of the network. But how effective is this register technology and is it possible to utilize more effective alternative of it? Let us consider the example of CREDITS platform where developers have abandoned Merkle trees. To begin with, we will learn general principles of Merkle Tree functioning. Overall, massive data structures which hash large amount of data elements are called Merkle Tree. To simplify this procedure these elements are summed into separate blocks which will be hashed further. These new blocks are hashed again and it continues till we receive only one block as the output. In practice, basic binary Merkle trees are applied most frequently, each block of it contains only 2 hashes. Nevertheless, what is the necessity of such a complicated procedure? Why we cannot sum all blocks immediately to obtain final root block? The point is that step-by-step hash algorithm allows to use Merkle proof which is the following: we can take any source block and track all stages of his hashing in the whole tree. In this way, we can check that all hasing rules are abided and each block placed right. It is easy to imagine such algorithm to be applied for a massive database. Assume that we have some archive which contains enormous amount of data. All of it is stored in the Merkle tree. The root of it must be in the public domain and authorized, for example, signed by lots of users or checked by large-scale computing capacities. So, requesting data about any cell of the archive user can Continue reading >>

Merry Merkle A Decentralized Giving Project Raising Funds Through Ethereum.

Merry Merkle A Decentralized Giving Project Raising Funds Through Ethereum.

0x5b4c3e8ff02896b0400e19adce5e10d2d82694b0 A Christmas tree lit up by crypto donations from around the world, powered by Ethereum. Merry Merkle tree is a decentralized giving project enabled by the Ethereum Blockchain. This holiday season, were challenging the Toronto and global crypto community's generosity in donating what they can to a Toronto homeless youth shelter (Covenant House) via the Merry Merkle Tree structure! Merry Merkle Initiative has raised over $200,000 CAD this holiday season in support of programs at Covenant House Toronto, Canadas largest agency serving at-risk, homeless and trafficked youth. This astounding contribution will make a huge difference in the lives of vulnerable youth by providing nearly nine months of food and shelter for approximately 100 youth a day. "We are truly grateful to everyone who came together to create an amazing event so that we could receive our very first cryptocurrency donations,-- says Bruce Rivers, Executive Director of Covenant House Toronto. The cryptocurrency community is an incredibly generous group of people, and this event just goes to show what a difference you can make when you team up in support of a cause." As Canadas largest agency serving at-risk, homeless and trafficked youth, Covenant House Toronto provides the widest range of services and support to as many as 250 youth a day. More than a place to stay, we provide 24/7 crisis shelter and transitional housing on-site and in the community, along with comprehensive services including education, counselling, health care, employment assistance, job training and aftercare. To do all this, we rely on donors for more than 80 percent of our $27-million annual operating budget. Our doors are open to youth 16 to 24 regardless of race, religion, sexual orientation, Continue reading >>

Developer Deep Diveetgate, Gateway Between Ethereum & Tendermint

Developer Deep Diveetgate, Gateway Between Ethereum & Tendermint

Developer Deep DiveETGate, Gateway between Ethereum & Tendermint [Post updated: Feb 16, 2018] This project is now defunct. The newer, more complete implementation of this idea is called Peggy . One of the most important functionalities of the Cosmos Network is IBC (Inter-Blockchain Communication protocol). It enables individual blockchains to communicate, allowing users to send tokens across zones such as sending pegged bitcoins to a smart contract on the Ethereum zone. The IBC protocol is meant to be a general-purpose communication protocol like TCP/IP. In theory, it could also be used to relay messages between parachains on Polkadot. (Then Polkadot could be a zone of Cosmos, and Cosmos could be a parachain of Polkadot.) But IBC can only be applied to blockchains whose consensus algorithms have transaction finality and efficient commit proofs. For those blockchains that do not, like that of Bitcoin or Ethereum, we have to build peg-zones in order to send assets from other chains to them. The idea is basically like that of a multi-party state-channel : we relay all headers and deposit/withdraw requests between chains. However, we can optimize it due to their architectural character. The concept of two-way-pegging generally describes a decentralized way to send cryptographic assets from one chain to another, like one would send money from one bank to another through nostro account s. In IBC, relayers continuously submit the headers of CHAIN_A to CHAIN_B and vice versa, allowing both chains to be aware of each others latest state. Consider the case that a user wants to send some bitcoin to Ethereum. The user will sign a special transfer transaction, locking their bitcoin. A few blocks later, the transaction will be confirmed, and the user can mint e-bitcoin on Ethereum w Continue reading >>

Raiden Specification

Raiden Specification

This document, just like the Raiden protocol is a constant work in progress Raiden is a payment network built on top of the ethereum network. The goal of the Raiden project is to provide an easy to use conduit for off-chain payments without the need of trust among the involved parties. While there are plans to extend Raiden to generalized state channels and channels with multiple parties, this documentation concerns only off-chain payment channels. How does the Raiden Network provide safety without trust? To achieve safety, all value transfers done off-chain must be backed up by value stored in the blockchain. Off-chain payments would be susceptible to double spending if that was not the case. The payment channel is represented in the blockchain by a smart contract which: Provides shared rules, agreed up-front by both parties, for the channels operation. Holds the token value in escrow to back the off-chain payments. Arbitrates disputes using rules that cannot be abused by one party. Given the above properties Raiden can safely do off-chain value transfers, knowing that once a dispute happens the smart contract can be used to settle and withdraw the token. The netting channel smart contract is the executable code that contains the shared rules for operating an off-chain payment channel. These rules are implicitly agreed upon by each participant whenever a channel is used. The netting channel allows for: A large number of bidirectional value transfers among the channel participants. Conditional value transfers that have an expiration and predefined rules to withdraw. Rules to determine ordering of transfers. Each netting channel backs a bi-directional off-chain payment channel. They deal with a predetermined token and each has its own settlement period configuration. An Continue reading >>

Merry Merkle A Decentralized Giving Project Raising Funds Through Ethereum.

Merry Merkle A Decentralized Giving Project Raising Funds Through Ethereum.

Merry Merkle Initiative is hoping to raise just $5,000 for a family of Syrian refugees recently arrived in Canada The family is just a few thousand dollars short of their target to pay basic expenses for their first year and build the foundations of a life in Canada. The family were working to support is a family of 4 from Syria, who arrived in Canada this December after years of waiting in a third country. The family came to Canada as part of the Private Sponsorship of Refugees Program . The father was a soccer coach, and the mother a gym teacher and former beautician. There are two children, boys aged 20 and 12. The older son was in IT school, and the younger in Grade 7. Your donations will go directly to the family to pay basic living expenses and help them build a life here in Canada. This includes learning english, school expenses for the children, driver training, and other costs. Having enough money to get this foundation under them will make a big difference for their stability and wellbeing over the long term. MADE WITH LOVE IN TORONTO, CANADA AND AROUND THE WORLD Special thanks to all the people in the community that came together to make this project come to life in only 1 week. Continue reading >>

State Trie - Ethereum Merkle Tree Explanation - Ethereum Stack Exchange

State Trie - Ethereum Merkle Tree Explanation - Ethereum Stack Exchange

Here is my basic understanding about how Ethereum stores transactions Then pairs are selected and a hash is generated for each pair This way the last remaining hash becomes the root Each block refers to its previous block's hash I am attaching the very common diagram showing this structure 1. The state root of Block 180994 is pointing to Block 180993's first left child of the state root. What does it mean and why is it needed? - First block 180993 is having a transaction where Account 98 is passing 30 ethers ether to Account 100 - Second block 180994 is having a transaction where Account 99 is passing 20 ethers to Account 100 How this will be reflected in the tree? Will there be similar kind of cross mapping of Merkle trees like shown in the diagram? Please explain The state has the information of all accounts in the blockchain, it is not stored in each block. The state is generated processing each block since the genesis block. Each block will only modify parts of the state. How to generate the state is defined in the yellow paper (pdf) . It is defined in such a way that it can be implemented in any programming language, and all such implementations will generate the same representation. It means the left side was not modified in block 180994. It is only a representation, remember the whole state is not stored, only the root hash. There's an article about Merkle Trees in Ethereum , I probably can't do better. The basic idea of merkle trees is that for a single operation it will only modify the minimum amount of nodes to recalculate the root hash. thanks for your answer! Here is my understand please share your views. 1. Each node is maintaining in total three trees. Each block is referring to one of the roots in that whole tree. 2. Based on the mapped root the state co Continue reading >>

Efficiently Bridging Evm Blockchains

Efficiently Bridging Evm Blockchains

My last article discussed the concept of a relay, which connects two Ethereum-based ( EVM ) blockchains together. A relay enables users to move their assets between the chains because those assets are replicated in both environments and map 1:1. Any number of separate blockchains may be joined to the Ethereum mainnet to offload transactions and scale the ecosystem to a much higher degree. This design is augmented by sharding and indirectly increases Ethereums capacity beyond what sharding itself allows. In this article I will discuss an updated version of my relay design. This is an exciting update because it makes two dramatic improvements: Relay data is packed much more efficiently. Instead of relaying each transaction, a Merkle root for a set of consecutive block headers is relayed with latency proportional to the cost of saving the hash. The centralized relayer is removed in lieu of a decentralized network of token stakers who run a standalone relay client, which can operate in a resource constrained environment with only moderate bandwidth requirements. Before introducing Relay Networks V2, I will review the concept of a relay. You can skip this part if you understand the concept of a relay. Relays have been discussed widely for a while under various names (bridges, sidechains, blockchain connectors). There are idiosyncrasies to every design, but the overarching concept is that you do something on one blockchain (e.g. depositing tokens) and prove it was done on another, which triggers some event on the new chain (e.g. withdrawing tokens). The first production example in the Ethereum world was BTC-Relay (built by Joseph Chow of ConsenSys in 2016), which connects the Bitcoin blockchain to the Ethereum blockchain. BTC-Relay works like this: Community members relay co Continue reading >>

Ethereum Classic Community

Ethereum Classic Community

Vitalik Buterin and The Ethereum Foundation create the first blockchain-based turing-complete smart contract platform Slock.it construct TheDAO Ethereum Contract; a security audit is completed by Dejavu TheDAO smart contract is deployed; members of the public send it value in return for DAO tokens Slock.it announce a $1.5 Million USD proposal, paid in Ether by the crowdfund, 'to guarantee the integrity of The DAO' On the last day of the crowdsale, DAO curator Vlad Zamfir calls for a moratorium on TheDAO, citing many game-theoretical security issues The crowdsale completes to become the world's largest and raising an incredible $150 Million USD Peter Vessenes publicly discloses the existence of a critical security vulnerability overlooked in many Solidiy contracts Stephan Tual publicly claims that TheDAO funds are safe despite the newly-discovered critical security flaw Ether is slowly and silently drained from TheDAO as the re-entry bug is applied The price of Ether is slashed in half as Griff Green announces that TheDAO has been hacked TheDAO's splitting mechanism gives around a month for a solution to be found that recovers the funds; Foundation and community developers race to implement a soft fork A group of 'white-hat' hackers secure 70% of TheDAO funds but protocol-level action is required to save the remaining 30% split by the hacker The Ethereum Foundation releases a 'Soft Fork' client to censor transactions coming from the hacker; mining pools vote to enable it by lowering gas limit Critical Denial of Service flaws are found in the Soft Fork implementation, miners quickly decide not to use it Many days of intense arguing goes on in the Ethereum community about the pros and cons of implementing a Hard Fork The only remaining option is a controversial Hard Fork. Continue reading >>

Merklepatriciatree.trie Merkle_patricia_tree V0.2.8

Merklepatriciatree.trie Merkle_patricia_tree V0.2.8

Elixir implementation of Ethereum's Merkle Patricia Tries. The encoding's specification can be found in the yellow paper or in the ethereum wiki under Appendix D. The modified patricia merkle trie allows arbitrary storage of key, value pairs with the benefits of a merkle trie in O(n*log(n)) time for insert, lookup and delete. This diagram is also very helpful in understanding these tries. The easiest way to add MerklePatriciaTree to your project is by using Mix . Add :merkle_patricia_tree as a dependency to your project's mix.exs: defp deps do [ {:merkle_patricia_tree, "~> 0.2.8"} ]end Use the MerklePatriciaTree module to create and build merkle patricia tries. You will be required to choosea storage database, and we currently support :ets and :leveldb. The follow example illustrates how tocreate an update a trie. ## Examples iex> trie = ...> MerklePatriciaTree.Test.random_ets_db() ...> |> MerklePatriciaTree.Trie.new() ...> |> MerklePatriciaTree.Trie.update(<<0x01::4, 0x02::4>>, "wee") ...> |> MerklePatriciaTree.Trie.update(<<0x01::4, 0x02::4, 0x03::4>>, "cool") iex> trie_2 = MerklePatriciaTree.Trie.update(trie, <<0x01::4, 0x02::4, 0x03::4>>, "cooler") iex> MerklePatriciaTree.Trie.get(trie, <<0x01::4, 0x02::4, 0x03::4>>) "cool" iex> MerklePatriciaTree.Trie.get(trie_2, <<0x01::4>>) nil iex> MerklePatriciaTree.Trie.get(trie_2, <<0x01::4, 0x02::4>>) "wee" iex> MerklePatriciaTree.Trie.get(trie_2, <<0x01::4, 0x02::4, 0x03::4>>) "cooler" iex> MerklePatriciaTree.Trie.get(trie_2, <<0x01::4, 0x02::4, 0x03::4, 0x04::4>>) nil Create your feature branch (git checkout -b my-new-feature) Commit your changes (git commit -am 'Add some feature') Push to the branch (git push origin my-new-feature) Continue reading >>

Merkling In Ethereum

Merkling In Ethereum

Merkle trees are a fundamental part of what makes blockchains tick. Although it is definitely theoretically possible to make a blockchain without Merkle trees, simply by creating giant block headers that directly contain every transaction, doing so poses large scalability challenges that arguably puts the ability to trustlessly use blockchains out of the reach of all but the most powerful computers in the long term. Thanks to Merkle trees, it is possible to build Ethereum nodes that run on all computers and laptops large and small, smart phones, and even internet of things devices such as those that will be produced by Slock.it . So how exactly do these Merkle trees work, and what value do they provide, both now and in the future? First, the basics. A Merkle tree, in the most general sense, is a way of hashing a large number of chunks of data together which relies on splitting the chunks into buckets, where each bucket contains only a few chunks, then taking the hash of each bucket and repeating the same process, continuing to do so until the total number of hashes remaining becomes only one: the root hash. The most common and simple form of Merkle tree is the binary Mekle tree, where a bucket always consists of two adjacent chunks or hashes; it can be depicted as follows: So what is the benefit of this strange kind of hashing algorithm? Why not just concatenate all the chunks together into a single big chunk and use a regular hashing algorithm on that? The answer is that it allows for a neat mechanism known as Merkle proofs: A Merkle proof consists of a chunk, the root hash of the tree, and the branch consisting of all of the hashes going up along the path from the chunk to the root. Someone reading the proof can verify that the hashing, at least for that branch, is c Continue reading >>

Ethereum's Mining Ecosystem Continues To Note Weekly Growth The Merkle

Ethereum's Mining Ecosystem Continues To Note Weekly Growth The Merkle

One particular aspect of cryptocurrency which people love to talk about is mining. The process of validating transactions and minting new coins has boggled the minds of enthusiasts for some time now. As such, its always interesting to keep an eye on mining trends. Things are looking pretty solid for Ethereum in this regard, although there are some minor concerns as well. According to recent statisticsfrom Huobi , there are some interesting developments in the world of Ethereum mining. Despite therecent price drop, there is no shortage of people mining Ether. Whether this is because they expect the price to go up, or simply becauseETH still remains more profitable to mine compared to other altcoins, is unclear. What is clear, however, isthat the average Ethereum network hashrate has not declined in the slightest,although it seems to have flattened out a bit as of late. From late March to early April, the Ethereum network hashrate increased by 0.72%. In the grand scheme of things, that may seem like a small gain, even though it further confirms people are still keeping a close eye on Ether as of right now.Some people claim that Bitmain has been mining massive amounts of Ether with its Ethereum ASIC miners over the past year and that it may soon begin to taper off. Those are merely rumors, though, and things may very well play out in a different manner. On the mining pool front, things have remained largely the same for Ethereum. The distribution of hashpower is still unchanged,although ViaBTC has become a lot less popular all of a sudden. Again, this may be related to the Bitmain ASICs, although it is impossible to confirm such speculation at this point. We did see an increase in the number of blocks mined last week, which is rather interesting. One worrisome sign isthat Continue reading >>

O Merkle Tree, O Merkle Tree: Ece Professor Linking Up With Ethereum Cryptography Community To Benefit Covenant House

O Merkle Tree, O Merkle Tree: Ece Professor Linking Up With Ethereum Cryptography Community To Benefit Covenant House

O Merkle Tree, O Merkle Tree: ECE professor linking up with Ethereum cryptography community to benefit Covenant House Professor Andreas Veneris and his research group are linking up with a group of cryptocurrency enthusiasts in Toronto to raise funds for Covenant House this holiday season University of Toronto Professor Andreas Veneri s and his research group in The Edward S. Rogers Sr. Department of Electrical & Computer Engineering (ECE) are working with a community of tech enthusiasts to encourage users of cryptocurrencies in Toronto to donate to Covenant House, Canadas largest agency serving homeless and trafficked youth. But these donors wont be opening their wallets or chequebooks theyll be donating cryptocurrency. Cryptocurrencies offer a decentralized digital method of exchange that is enabled by blockchain technology a mechanism for ensuring information is validated by employing a large network of individual, distributed and independent computers. One such cryptocurrency is ether the value token of the Ethereum blockchain. This blockchain technology is enabling a unique philanthropic project to benefit the Toronto community. Professor Veneris and his research group as well as organizations like L4, Blockgeeks and Truebit have linked up to organize what they are calling the Merry Merkle Tree event. Theyve constructed a specialized Christmas tree that will interact with the Etherium blockchain donations sent to the Merry Merkle Tree project will activate lights on the tree at the Assembly Chefs Hall in Toronto on Thursday December 21, starting at 7:00 p.m. My research is on verification of smart contracts, environmentally-friendly scalability of blockchain and also how blockchain technology impacts our social structure, our privacy and our regulation, says Profe Continue reading >>

Talk About Merkle Tree By Ethereum

Talk About Merkle Tree By Ethereum

Merkle trees are an essential part of the blockchain. Although theoretically it is possible to have a blockchain without Merkel trees, you can do that by creating a block header that directly contains each transaction, but Doing so undoubtedly poses the challenge of scalability, and in the long run, there may eventually only be the most powerful computers that can run these unbelievable blockchain. It is with Merkel trees that Ethereum nodes can be set up to run on all computers, laptops, smartphones, and even those that are manufactured by Slock.it. So what exactly does the Merkle tree do, what value can they provide, now and in the future? First of all, let's talk about the basics. Merkle tree, in a general sense, is a way of hashing a large number of chunks of data that relies on splitting these data "chunks" into smaller chunks of data, each A bucket block contains only a few data "blocks", and then re-hashes each bucket unit data block, repeating the same process until the total number of remaining hashes becomes only 1: root hash ( root hash ). Merkel trees The most common and simple form of a Merkle tree is the binary Mekle tree , where the data block of a bucket always contains two adjacent blocks or hash, which is described as follows: so, this strange hash algorithm what good it? Why not directly concatenate these data blocks into a single chunk, using the conventional hash algorithm? The answer is that it allows a neat mechanism, we call Merkel proof ( Merkle proofs ): Merkel a data block contains a proof, Zheke The root hash of the Merkel tree, and the "branch" that contains all the hashes along the data block to the root path. Some people think that this proof can verify the process of the hash, at least for the branch. The application is also simple: Supp Continue reading >>

Growing A Merkle Tree

Growing A Merkle Tree

Ethereum is a platform and a programming language that makes it possible for any developer to build and publish next-generation distributed applications. Ether, Ethereum's cryptofuel, powers the applications on the decentralized network. import Data.ByteStringimport Ethereum.Word4type Key = [Word4] -- hexadecimal digitstype Value = ByteStringdefaultValue = ByteString.empty lookup :: Key -> AssocList -> Valuelookup key = fromMaybe defaultValue . Prelude.lookup key update :: Key -> Value -> AssocList -> AssocListupdate key value list = (key, value) : list -- TODO: handle duplicates, default values data Trie = Branch [Trie] Value -- 16-element list | Empty lookup :: Trie -> Key -> Valuelookup Empty _ = defaultValuelookup (Branch _ value) [] = valuelookup (Branch children _) (nibble : rest) = let child = genericIndex children nibble in lookup child rest data Trie = Branch [Trie] Value | Shortcut [Word4] (Either Trie Value) | Emptylookup :: Trie -> Key -> Valuelookup (Shortcut prefix result) key = case (stripPrefix prefix key, result) of (Just [], Right value) -> value (Just suffix, Left child) -> lookup child suffix _ -> defaultValuelookup _ _ = ... Shortcut prefix (Right defaultValue) --> Empty Branch (replicate 16 Empty) value --> Shortcut [] (Right value) [...] a hash tree or Merkle tree is a tree in which every non-leaf node is labelled with the hash of the labels of its children nodes. Hash trees are useful because they allow efficient and secure verification of the contents of large data structures. newtype Hash = Hash ByteStringdata Trie = Branch [Hash] Value | Shortcut [Word4] (Either Value Hash) | Empty lookup :: Hash -> Key -> Valuelookup hash key = ??? lookup :: Hash -> Key -> IO Valuelookup root key = retrieveNode root >>= getVal where getVal Empty = return def Continue reading >>

Ethereum's Compact Merkle Trie | Hacker News

Ethereum's Compact Merkle Trie | Hacker News

Weird coincidence: this post uses Sputter, an EVM implementation written in Clojure, and there's a Clojure-inspired Lisp named "Sputter" at the top of /r/golang right now. Threw me for a loop. Maybe with some tweaking, you could run Sputter in Sputter? Not that weird of a coincidence, right? The words lisp and sputter are both related to speech, so I wasn't being overly creative when I came up with the name. I wouldn't recommend using my incarnation of sputter just yet. It's not even close to being production-ready and it's purely interpreted right now and rather slow. Merkle trees are used extensively in distributed computing. Here's an example: You have many instances serving assets of some kind replicated in several data centers. They are structured in an arbitrary number of branches with many assets in each branch: (root) | \ (foo) (bar)---(baz)----[even_more_assets] | | | [many_more_assets] | [many_assets] How do you make sure the asset trees in the instances are synced up, serving the same assets? You could compare every bit across every instance, but that would be very inefficient. You could compare the hashes of all the assets at each node of the tree, but you would still end up making many unnecessary comparisons. You can simply hash each node of the tree based on the hash of its child nodes / assets. This forms a Merkle tree. That way, you can simply compare the root hashes across instances, and if they match, then the whole asset tree must be the same. If they don't match, compare the hashes at the next level of the tree until you find the discrepancy, and sync the nodes / assets where the hashes don't match. Merkle trees can be a very powerful tool for reaching consensus quickly in distributed systems. Continue reading >>

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