The Digitstandard is trying to build a new type of currency that will combine the advantages of gold, blockchain-like (e.g. Bitcoin), and the modern consensus of money economics. The main purpose of this standard are:
1. Resolving the problem issued among the money-printing competitions, financial crises and trade wars;
2. Setting up a new type of National Reserve Currency base on nearly zero reserve and transaction cost;
3. Setting up a new economy order for the future.
After the crack down of Bretton Woods system, the world is maintaining the economic order base on US Dollar for decades, which gradually has several issues especially after the quantitative easing. Every country started to print Trillions of cash in order to prevent from being hurt by others’ monetary policies, which led to the more serious problem brewing within. One way to make a better change is to have a new standard can be influenced by more countries together rather than just US Dollar, kind like the board of a company.
Though gold is out of date for the standard function, most of the countries are still having mechanism of reserving gold. Obviously, there are so many disadvantages of that, high cost of reservation, safety issues, and transportation. From the historical perspective, the reasons to use gold as currency can be met by the digital currencies in the light of the Blockchain-like technology but without those weakness. What we have are the changing of the notions and the continuous improving of the detail of the construction.
Now it’s the era of technology, the world is changing faster and faster and the exploration radius of human is getting further and further. Can we still use gold as the hard currency when we colonize other planets?
A Creative Decentralized Trust & Secured & Unchangeable Ledger System
Blockchain was invented by Satoshi Nakamoto in 2008 for use in the cryptocurrency bitcoin, as its public transaction ledger.
A blockchain, originally block chain, is a continuously growing list of records, called blocks, which are linked and secured using cryptography. Each block typically contains a cryptographic hash of the previous block, a timestamp and transaction data. By design, a blockchain is inherently resistant to modification of the data. It is "an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way". For use as a distributed ledger, a blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without the alteration of all subsequent blocks, which requires collusion of the network majority.
Blockchains are secure by design and are an example of a distributed computing system with high Byzantine fault tolerance. Decentralized consensus has therefore been achieved with a blockchain. This makes blockchains potentially suitable for the recording of events, medical records, and other records management activities, such as identity management, transaction processing, documenting provenance, food traceability or voting.
Blocks hold batches of valid transactions that are hashed and encoded into a Merkle tree. Each block includes the cryptographic hash of the prior block in the blockchain, linking the two. The linked blocks form a chain. This iterative process confirms the integrity of the previous block, all the way back to the original genesis block.
Sometimes separate blocks can be produced concurrently, creating a temporary fork. In addition to a secure hash-based history, any blockchain has a specified algorithm for scoring different versions of the history so that one with a higher value can be selected over others. Blocks not selected for inclusion in the chain are called orphan blocks. Peers supporting the database have different versions of the history from time to time. They only keep the highest-scoring version of the database known to them. Whenever a peer receives a higher-scoring version (usually the old version with a single new block added) they extend or overwrite their own database and retransmit the improvement to their peers. There is never an absolute guarantee that any particular entry will remain in the best version of the history forever. Because blockchains are typically built to add the score of new blocks onto old blocks and because there are incentives to work only on extending with new blocks rather than overwriting old blocks, the probability of an entry becoming superseded goes down exponentially as more blocks are built on top of it, eventually becoming very low. For example, in a blockchain using the proof-of-work system, the chain with the most cumulative proof-of-work is always considered the valid one by the network. There are a number of methods that can be used to demonstrate a sufficient level of computation. Within a blockchain the computation is carried out redundantly rather than in the traditional segregated and parallel manner.
♦ Hard forks
A hard fork occurs when a blockchain splits into two incompatible separate chains. This is a consequence of the use of two incompatible sets of rules trying to govern the system. For example, Ethereum has hard-forked to "make whole" the investors in The DAO, which had been hacked by exploiting a vulnerability in its code. In 2014 the NXT community was asked to consider a hard fork that would have led to a rollback of the blockchain records to mitigate the effects of a theft of 50 million NXT from a major cryptocurrency exchange. The hard fork proposal was rejected, and some of the funds were recovered after negotiations and ransom payment.
By storing data across its network, the blockchain eliminates the risks that come with data being held centrally. The decentralized blockchain may use ad-hoc message passing and distributed networking.
Its network lacks centralized points of vulnerability that computer crackers can exploit; likewise, it has no central point of failure. Blockchain security methods include the use of public-key cryptography. A public key (a long, random-looking string of numbers) is an address on the blockchain. Value tokens sent across the network are recorded as belonging to that address. A private key is like a password that gives its owner access to their digital assets or the means to otherwise interact with the various capabilities that blockchains now support. Data stored on the blockchain is generally considered incorruptible.
This is where blockchain has its advantage. While centralized data is more controllable, information and data manipulation are common. By decentralizing it, blockchain makes data transparent to everyone involved.
Every node in a decentralized system has a copy of the blockchain. Data quality is maintained by massive database replication and computational trust. No centralized "official" copy exists and no user is "trusted" more than any other. Transactions are broadcast to the network using software. Messages are delivered on a best-effort basis. Mining nodes validate transactions, add them to the block they are building, and then broadcast the completed block to other nodes. Blockchains use various time-stamping schemes, such as proof-of-work, to serialize changes. Alternate consensus methods include proof-of-stake. Growth of a decentralized blockchain is accompanied by the risk of node centralization because the computer resources required to process larger amounts of data become more expensive.
Open blockchains are more user-friendly than some traditional ownership records, which, while open to the public, still require physical access to view. Because all early blockchains were permissionless, controversy has arisen over the blockchain definition. An issue in this ongoing debate is whether a private system with verifiers tasked and authorized (permissioned) by a central authority should be considered a blockchain. Proponents of permissioned or private chains argue that the term "blockchain" may be applied to any data structure that batches data into time-stamped blocks. These blockchains serve as a distributed version of multiversion concurrency control (MVCC) in databases. Just as MVCC prevents two transactions from concurrently modifying a single object in a database, blockchains prevent two transactions from spending the same single output in a blockchain. Opponents say that permissioned systems resemble traditional corporate databases, not supporting decentralized data verification, and that such systems are not hardened against operator tampering and revision. Nikolai Hampton of Computerworld said that "many in-house blockchain solutions will be nothing more than cumbersome databases." Business analysts Don Tapscott and Alex Tapscott define blockchain as a distributed ledger or database open to anyone.
The great advantage to an open, permissionless, or public, blockchain network is that guarding against bad actors is not required and no access control is needed. This means that applications can be added to the network without the approval or trust of others, using the blockchain as a transport layer.
Bitcoin and other cryptocurrencies currently secure their blockchain by requiring new entries including a proof of work. To prolong the blockchain, bitcoin uses Hashcash puzzles developed by Adam Back in the 1990s.
Financial companies have not prioritised decentralized blockchains. In 2016, venture capital investment for blockchain related projects was weakening in the USA but increasing in China. Bitcoin and many other cryptocurrencies use open (public) blockchains. As of January 2018, bitcoin has the highest market capitalization.
♦ Permissioned (private) blockchain
Permissioned blockchains use an access control layer to govern who has access to the network. In contrast to public blockchain networks, validators on private blockchain networks are vetted by the network owner. They do not rely on anonymous nodes to validate transactions nor do they benefit from the network effect.[better source needed] Permissioned blockchains can also go by the name of 'consortium' or 'hybrid' blockchains.
The New York Times noted in both 2016 and 2017 that many corporations are using blockchain networks "with private blockchains, independent of the public system."
Nikolai Hampton pointed out in Computerworld that "There is also no need for a "51 percent" attack on a private blockchain, as the private blockchain (most likely) already controls 100 percent of all block creation resources. If you could attack or damage the blockchain creation tools on a private corporate server, you could effectively control 100 percent of their network and alter transactions however you wished." This has a set of particularly profound adverse implications during a financial crisis or debt crisis like the financial crisis of 2007–08, where politically powerful actors may make decisions that favor some groups at the expense of others. And "the bitcoin blockchain is protected by the massive group mining effort. It's unlikely that any private blockchain will try to protect records using gigawatts of computing power — it's time consuming and expensive." He also said, "Within a private blockchain there is also no 'race'; there's no incentive to use more power or discover blocks faster than competitors. This means that many in-house blockchain solutions will be nothing more than cumbersome databases."
First Cryptocurrency & Limit to 21Million
It is the first decentralized digital currency, as the system works without a central bank or single administra tor. The network is peer-to-peer and transactions take place between users directly, without an intermediary. These transactions are verified by network nodes through the use of cryptography and recorded in a public distributed ledger called a blockchain.Bitcoins are created as a reward for a process known as mining. They can be exchanged for other currencies, products, and services.
Bitcoin was invented by an unknown person or group of people under the name Satoshi Nakamoto and released as open-source software in 2009.
Transactions are defined using a Forth-like scripting language. Transactions consist of one or more inputs and one or more outputs. When a user sends bitcoins, the user designates each address and the amount of bitcoin being sent to that address in an output. To prevent double spending, each input must refer to a previous unspent output in the blockchain. The use of multiple inputs corresponds to the use of multiple coins in a cash transaction. Since transactions can have multiple outputs, users can send bitcoins to multiple recipients in one transaction. As in a cash transaction, the sum of inputs (coins used to pay) can exceed the intended sum of payments. In such a case, an additional output is used, returning the change back to the payer. Any input satoshis not accounted for in the transaction outputs become the transaction fee.
In the blockchain, bitcoins are registered to bitcoin addresses. Creating a bitcoin address is nothing more than picking a random valid private key and computing the corresponding bitcoin address. This computation can be done in a split second. But the reverse (computing the private key of a given bitcoin address) is mathematically unfeasible and so users can tell others and make public a bitcoin address without compromising its corresponding private key. Moreover, the number of valid private keys is so vast that it is extremely unlikely someone will compute a key-pair that is already in use and has funds. The vast number of valid private keys makes it unfeasible that brute force could be used for that. To be able to spend the bitcoins, the owner must know the corresponding private key and digitally sign the transaction. The network verifies the signature using the public key.
If the private key is lost, the bitcoin network will not recognize any other evidence of ownership; the coins are then unusable, and effectively lost. For example, in 2013 one user claimed to have lost 7,500 bitcoins, worth $7.5 million at the time, when he accidentally discarded a hard drive containing his private key. A backup of his key(s) would have prevented this.
Mining is a record-keeping service done through the use of computer processing power. Miners keep the blockchain consistent, complete, and unalterable by repeatedly grouping newly broadcast transactions into a block, which is then broadcast to the network and verified by recipient nodes. Each block contains a SHA-256 cryptographic hash of the previous block, thus linking it to the previous block and giving the blockchain its name.
To be accepted by the rest of the network, a new block must contain a so-called proof-of-work. The system used is based on Adam Back's 1997 anti-spam scheme, Hashcash. The PoW requires miners to find a number called a nonce, such that when the block content is hashed along with the nonce, the result is numerically smaller than the network's difficulty target. This proof is easy for any node in the network to verify, but extremely time-consuming to generate, as for a secure cryptographic hash, miners must try many different nonce values (usually the sequence of tested values is the ascending natural numbers: 0, 1, 2, 3, ...) before meeting the difficulty target.
Every 2,016 blocks (approximately 14 days at roughly 10 min per block), the difficulty target is adjusted based on the network's recent performance, with the aim of keeping the average time between new blocks at ten minutes. In this way the system automatically adapts to the total amount of mining power on the network. Between 1 March 2014 and 1 March 2015, the average number of nonces miners had to try before creating a new block increased from 16.4 quintillion to 200.5 quintillion.
The proof-of-work system, alongside the chaining of blocks, makes modifications of the blockchain extremely hard, as an attacker must modify all subsequent blocks in order for the modifications of one block to be accepted. As new blocks are mined all the time, the difficulty of modifying a block increases as time passes and the number of subsequent blocks (also called confirmations of the given block) increases.
The successful miner finding the new block is rewarded with newly created bitcoins and transaction fees. As of 9 July 2016, the reward amounted to 12.5 newly created bitcoins per block added to the blockchain. To claim the reward, a special transaction called a coinbase is included with the processed payments. All bitcoins in existence have been created in such coinbase transactions. The bitcoin protocol specifies that the reward for adding a block will be halved every 210,000 blocks (approximately every four years). Eventually, the reward will decrease to zero, and the limit of 21 million bitcoins will be reached c. 2140; the record keeping will then be rewarded by transaction fees solely.
In other words, bitcoin's inventor Nakamoto set a monetary policy based on artificial scarcity at bitcoin's inception that there would only ever be 21 million bitcoins in total. Their numbers are being released roughly every ten minutes and the rate at which they are generated would drop by half every four years until all were in circulation.
A wallet stores the information necessary to transact bitcoins. While wallets are often described as a place to hold or store bitcoins, due to the nature of the system, bitcoins are inseparable from the blockchain transaction ledger. A better way to describe a wallet is something that "stores the digital credentials for your bitcoin holdings" and allows one to access (and spend) them. Bitcoin uses public-key cryptography, in which two cryptographic keys, one public and one private, are generated. At its most basic, a wallet is a collection of these keys.
There are several types of wallets. Software wallets connect to the network and allow spending bitcoins in addition to holding the credentials that prove ownership. Software wallets can be split further in two categories: full clients and lightweight clients.
Full clients verify transactions directly on a local copy of the blockchain (over 150 GB As of January 2018), or a "pruned" subset of the blockchain (around half a gigabyte). They are the most secure and reliable way of using the network, as trust in external parties is not required. Full clients check the validity of mined blocks, preventing them from transacting on a chain that breaks or alters network rules. Because of its size and complexity, storing the entire blockchain is not suitable for all computing devices.
Lightweight clients, on the other hand, consult full clients to send and receive transactions without requiring a local copy of the entire blockchain (see simplified payment verification – SPV). This makes lightweight clients much faster to set up and allows them to be used on low-power, low-bandwidth devices such as smartphones. When using a lightweight wallet, however, the user must trust the server to a certain degree, as it can report faulty values back to the user. Lightweight clients follow the longest blockchain and do not ensure it is valid, requiring trust in miners.
With both types of software wallets, the users are responsible for keeping their private keys in a secure place.
Besides software wallets, Internet services called online wallets offer similar functionality but may be easier to use. In this case, credentials to access funds are stored with the online wallet provider rather than on the user's hardware. As a result, the user must have complete trust in the wallet provider. A malicious provider or a breach in server security may cause entrusted bitcoins to be stolen. An example of such security breach occurred with Mt. Gox in 2011.
Physical wallets store the credentials necessary to spend bitcoins offline. Examples combine a novelty coin with these credentials printed on metal. Paper wallets are simply paper printouts. Another type of wallet called a hardware wallet keeps credentials offline while facilitating transactions.
Bitcoin is pseudonymous, meaning that funds are not tied to real-world entities but rather bitcoin addresses. Owners of bitcoin addresses are not explicitly identified, but all transactions on the blockchain are public. In addition, transactions can be linked to individuals and companies through "idioms of use" (e.g., transactions that spend coins from multiple inputs indicate that the inputs may have a common owner) and corroborating public transaction data with known information on owners of certain addresses. Additionally, bitcoin exchanges, where bitcoins are traded for traditional currencies, may be required by law to collect personal information.
To heighten financial privacy, a new bitcoin address can be generated for each transaction. For example, hierarchical deterministic wallets generate pseudorandom "rolling addresses" for every transaction from a single seed, while only requiring a single passphrase to be remembered to recover all corresponding private keys. Researchers at Stanford University and Concordia University have also shown that bitcoin exchanges and other entities can prove assets, liabilities, and solvency without revealing their addresses using zero-knowledge proofs.
Smart Contract & No Hard Cap
Proposed in late 2013 by Vitalik Buterin, a cryptocurrency researcher and programmer, Ethereum is an open-source, public, blockchain-based distributed computing platform and operating system featuring smart contract (scripting) functionality. It supports a modified version of Nakamoto consensus via transaction based state transitions. The system went live on 30 July 2015, with 11.9 million coins "premined" for the crowdsale. This accounts for approximately 13 percent of the total circulating supply. In 2016, as a result of the collapse of The DAO project, Ethereum was split into two separate blockchains – the new separate version became Ethereum (ETH), and the original continued as Ethereum Classic (ETC).
Ethereum provides a decentralized Turing-complete virtual machine, the Ethereum Virtual Machine (EVM), which can execute scripts using an international network of public nodes. "Gas", an internal transaction pricing mechanism, is used to mitigate spam and allocate resources on the network. As with other cryptocurrencies, the validity of each ether is provided by a blockchain, which is a continuously growing list of records, called blocks, which are linked and secured using cryptography. By design, the blockchain is inherently resistant to modification of the data. It is an open, distributed ledger that records transactions between two parties efficiently and in a verifiable and permanent way. Unlike Bitcoin, Ethereum operates using accounts and balances in a manner called state transitions. This does not rely upon UTXOs. State denotes the current balances of all accounts and extra data. State is not stored on the blockchain, it is stored in a separate Merkle Patricia tree. A cryptocurrency wallet stores the public and private "keys" or "addresses" which can be used to receive or spend Ether. These can be generated through BIP 39 style mnemonics for a BIP 32 "HD Wallet". In Ethereum, this is unnecessary as it does not operate in a UTXO scheme. With the private key, it is possible to write in the blockchain, effectively making an ether transaction. To send ether to an account, you need the public key of that account. Ether accounts are pseudonymous in that they are not linked to individual persons, but rather to one or more specific addresses. Owners can store these addresses in software, on paper and possibly in memory ("brain wallet").
♦ Comparison to bitcoin
Ether is different from Bitcoin in several aspects:
• Its block time is 14 to 15 seconds, compared with 10 minutes for bitcoin.
• Mining of ether generates new coins at a usually consistent rate, occasionally changing during hard forks, while for bitcoin the rate halves every 4 years.
• Transaction fees differ by computational complexity, bandwidth use and storage needs (in a system known as gas), while bitcoin transactions compete by means of transaction size, in bytes.
• Ethereum gas units each have a price that can be specified in a transaction. This is typically measured in Gwei. Bitcoin transactions usually have fees specified in satoshis per byte.
• Transaction fees are generally considerably lower for ether than for Bitcoin. In December 2017, the median transaction fee for ether corresponded to $0.33, while for bitcoin it corresponded to $23.
• Ethereum uses an account system where values in Wei are debited from accounts and credited to another, as opposed to Bitcoin's UTXO system, which is more analogous to spending cash and receiving change in return. Both systems have their pros and cons; in terms of storage space, complexity, and security/anonymity.
• Ethereum is planned to transfer to full Proof-of-Stake, currently it is a hybrid between Proof-of-Work and Proof-of-Stake. This scheme is commonly known as Casper Friendly Finality Gadget (FFG), whereas the pure Proof-of-Stake system is known as Casper Correct-by-Construction (CBC). Mining becomes obsolete during Casper CBC, via an exponential difficulty bomb in Ethash.
♦ Comparison to bitcoin
♦ Smart contracts
Smart contracts can be public, which opens up the possibility to prove functionality, e.g. self-contained provably fair casinos.
One issue related to using smart contracts on a public blockchain is that bugs, including security holes, are visible to all but cannot be fixed quickly. One example of this is the 17 June 2016 attack on The DAO, which could not be quickly stopped or reversed.
There is ongoing research on how to use formal verification to express and prove non-trivial properties. A Microsoft Research report noted that writing solid smart contracts can be extremely difficult in practice, using The DAO hack to illustrate this problem. The report discussed tools that Microsoft had developed for verifying contracts, and noted that a large-scale analysis of published contracts is likely to uncover widespread vulnerabilities. The report also stated that it is possible to verify the equivalence of a Solidity program and the EVM code.
Semi-decentralized & Bank-supportive
Ripple is a real-time gross settlement system (RTGS), currency exchange and remittance network by Ripple. Also called the Ripple Transaction Protocol (RTXP) or Ripple protocol, it is built upon a distributed open source Internet protocol, consensus ledger and native cryptocurrency called XRP (ripples). Released in 2012, Ripple purports to enable "secure, instantly and nearly free global financial transactions of any size with no chargebacks." It supports tokens representing fiat currency, cryptocurrency, commodity or any other unit of value such as frequent flier miles or mobile minutes. At its core, Ripple is based around a shared, public database or ledger, which uses a consensus process that allows for payments, exchanges and remittance in a distributed process.
Ripple's website describes the open-source protocol as "basic infrastructure technology for interbank transactions – a neutral utility for financial institutions and systems." The protocol allows banks and non-bank financial services companies to incorporate the Ripple protocol into their own systems, and therefore allow their customers to use the service. Currently, Ripple requires two parties for a transaction to occur: first, a regulated financial institution "holds funds and issues balances on behalf of customers." Second, "market makers" such as hedge funds or currency trading desks provide liquidity in the currency they want to trade in. At its core, Ripple is based around a shared, public database or ledger that has its contents decided on by consensus. In addition to balances, the ledger holds information about offers to buy or sell currencies and assets, creating the first distributed exchange. The consensus process allows for payments, exchanges and remittance in a distributed process. According to the CGAP in 2015, "Ripple does for payments what SMTP did for email, which is enable the systems of different financial institutions to communicate directly."
In Ripple, users make payments between each other by using cryptographically signed transactions denominated in either fiat currencies or Ripple's internal currency (XRP). For XRP-denominated transactions Ripple can make use of its internal ledger, while for payments denominated in other assets, the Ripple ledger only records the amounts owed, with assets represented as debt obligations. As originally Ripple only kept records in its ledger and has no real-world enforcement power, trust was required. However, Ripple is now integrated with various user verification protocols and bank services. Users have to specify which other users they trust and to what amount. When a non-XRP payment is made between two users that trust each other, the balance of the mutual credit line is adjusted, subject to limits set by each user. In order to send assets between users that have not directly established a trust relationship, the system tries to find a path between the two users such that each link of the path is between two users that do have a trust relationship. All balances along the path are then adjusted simultaneously and atomically. This mechanism of making payments through a network of trusted associates is named 'rippling'. It has similarities to the age-old hawala system.
A gateway is any person or organization that enables users to put money into and take money out of Ripple's liquidity pool. A gateway accepts currency deposits from users and issues balances into Ripple's distributed ledger. Furthermore, gateways redeem ledger balances against the deposits they hold when currency is withdrawn. In practice, gateways are similar to banks, yet they share one global ledger known as the Ripple protocol. Depending on the type and degree of interaction a user has with a gateway, the gateway may have anti-money laundering (AML) or know your customer (KYC) policies requiring verification of identification, address, nationality, etc. to prevent criminal activity. Popular gateways as of 2017 included Bitstamp, Gatehub, Ripple Fox, Tokyo JPY, Mr. Ripple, RippleChina and The Rock Trading.
♦ Trustlines and rippling
Users must ‘extend trust’ to the Ripple gateway that holds their deposit. This manual creation of a trustline indicates to the Ripple network that the user is comfortable with the gateway’s counterparty risk. Furthermore, the user must put a quantitative limit on this trust and create a similar limit for each currency on deposit at that gateway. For example, if a user deposits US$50 and BTC2.00 at The Rock Trading, the user will have to grant trust of at least that much in both currencies to the gateway for the monies to be available in the Ripple network. When a user has allowed multiple gateways in the same currency, there is an advanced option to allow "rippling," which subjects the user’s balance of that currency to switch (or ripple) between gateways. Though their total balance doesn't alter, users earn a small transit fee for providing inter-gateway liquidity
♦ Consensus ledger
Ripple relies on a common shared ledger, which is a distributed database storing information about all Ripple accounts. The network is "managed by a network of independent validating servers that constantly compare their transaction records." Servers could belong to anyone, including banks or market makers. Though the Ripple protocol is freeware, Ripple Labs continues to develop and promote the Ripple protocol, which confirms financial transactions via a network of distributed servers. Ripple Labs is currently assisting banks in integrating with the Ripple network. A new ledger is created every few seconds, and the last closed ledger is a perfect record of all Ripple accounts as determined by the network of servers. A transaction is any proposed change to the ledger and can be introduced by any server to the network. The servers attempt to come to consensus about a set of transactions to apply to the ledger, creating a new ‘last closed ledger’.
The consensus process is distributed, and the goal of consensus is for each server to apply the same set of transactions to the current ledger. Servers continually receive transactions from other servers on the network, and the server determines which transactions to apply based on if a transaction came from a specified node in the ‘unique node list’ (UNL). Transactions that are agreed upon by a "supermajority" of peers are considered validated. If the supermajority isn't in consensus, "this implies that transaction volume was too high or network latency too great for the consensus process to produce consistent proposals," then the consensus process is again attempted by the nodes. Each round of consensus reduces disagreement, until the supermajority is reached. The intended outcome of this process is that disputed transactions are discarded from proposals while widely accepted transactions are included. While users may assemble their own UNL nodes and have full control over which nodes they trust, Ripple Labs acknowledges that most people will use the default UNL supplied by their client.
♦ Ledger security
In early 2014, a rival company called the Stellar Foundation experienced a network crash. The company brought in David Mazieres, Stellar's chief scientist and head of Stanford University's secure computing group, to conduct a review of the Stellar consensus system, which was similar to Ripple's. Mazieres declared the Stellar system unlikely to be safe when operating with "more than one validating node," arguing that when consensus is not reached, a ledger fork occurs with parts of the network disagreeing over accepted transactions. The Stellar Foundation afterwards claimed that there was an "innate weaknesses" in the consensus process, a claim which according to Finance Magnates, "Ripple vehemently denied." Ripple Labs chief cryptographer David Schwartz disputed Mazieres' findings and declared that Stellar had incorrectly implemented the consensus system, as "the protocol provides safety and fault tolerance assuming the validators are configured correctly." The company further wrote that after examining Stellar's information, they had concluded "that there is no threat to the continued operation of the Ripple network."
♦ Use as a payment/forex system
Ripple allows users or businesses to conduct cross-currency transactions in 3 to 5 seconds. All accounts and transactions are cryptographically secure and algorithmically verified. Payments can only be authorized by the account holder and all payments are processed automatically without any third parties or intermediaries. Ripple validates accounts and balances instantly for payment transmission and delivers payment notification with very little latency (within a few seconds). Payments are irreversible, and there are no chargebacks. XRP cannot be frozen or seized. While as of 2014 anyone could open an account on Ripple, by 2015 identity verification procedures had been implemented. Ripple's Path-finding Algorithm searches for the fastest, cheapest path between two currencies. In the case of a user who wants to send a payment from USD to EUR, this could be a "one-hop" path directly from USD to EUR, or it could be a multi-hop path, perhaps from USD to CAD to XRP to EUR. Path finding is designed to seek out the cheapest conversion cost for the user. As of May 14, 2014, Ripple's gateways allow deposits in a limited number of fiat currencies (USD, EUR, MXN, NZD, GBP, NOK, JPY, CAD, CHF, CNY, AUD), a handful of crypto currencies (BTC, XRP, LTC, NMC, NXT, PPC, XVN, SLL) and a few commodities (gold, silver, platinum).
♦ The Bitcoin Bridge
The bitcoin bridge is a link between the Ripple and bitcoin ecosystems. The bridge makes it possible to pay any bitcoin user straight from a Ripple account without ever needing to hold any of the digital currency. Additionally, any merchant accepting bitcoins has the potential to accept any currency in the world. For example, a Ripple user may prefer to keep money in USD and not own bitcoins. A merchant, however, may desire payment in bitcoin. The bitcoin bridge allows any Ripple user to send bitcoins without having to use a central exchange such as BTC-e to acquire them. Bitstamp acts as a gateway for the Ripple payment protocol, among other exchanges.
♦ Market makers
Any user on Ripple can act as a market maker by offering an arbitrage service such as providing market liquidity, intra-gateway currency conversion, rippling, etc. Market makers can also be hedge funds or currency trading desks. According to the Ripple website, "by holding balances in multiple currencies and connecting to multiple gateways, market makers facilitate payments between users where no direct trust exists, enabling exchanges across gateways." With a sufficient number of market makers, the path finding algorithm creates a near frictionless market and enables users to seamlessly pay each other via the network in different currencies, without assuming any undesired foreign exchange risk.
Ripple can be used to trade or convert currencies, to send money in one currency and the recipient to receive it in another currency. For example, a user can pay with USD and the recipient can choose to receive the money in another currency, including bitcoins and XRP.
♦ As a bridge currency
One of the specific functions of XRP is as a bridge currency, which can be necessary if no direct exchange is available between two currencies at a specific time, for example when transacting between two rarely traded currency pairs. Within the network’s currency exchange, XRP are traded freely against other currencies, and its market price fluctuates against dollars, euros, yen, bitcoin, etc. Ripple's design focus is as a currency exchange and a distributed-RTGS, as opposed to emphasizing XRP as an alternative currency. In April 2015, Ripple Labs announced that a new feature called autobridging had been added to Ripple, with the intent of making it easier for market makers to transact between rarely traded currency pairs. The feature is also intended to expose more of the network to liquidity and better FX rates.
♦ Anti-spam measure
When a user conducts a financial transaction in a non-native currency, Ripple charges a transaction fee. The purpose of the fees is to protect against network flooding by making the attacks too expensive for hackers. If Ripple were completely free to access, adversaries could broadcast large amounts of "ledger spam" (i.e. fake accounts) and "transaction spam" (i.e. fake transactions) in an attempt to overload the network. This could cause the size of the ledger to become unmanageable and interfere with the network’s ability to quickly settle legitimate transactions. Thus, to engage in trade, each Ripple account is required to have a small reserve of 20 XRP, and a transaction fee starting at .00001 XRP (US$0.000002 as of December 5, 2017 must be spent for each trade. This transaction fee is not collected by anyone; the XRP is destroyed and ceases to exist. The transaction fee rises if the user posts trades at an enormous rate (many thousands per minute), and resettles after a period of inactivity.
♦ Reactions to XRP
The reaction to XRP is polarized in the crypto-currency community. Proponents of bitcoin have criticized XRP for being "pre-mined," as XRP is built directly into the Ripple protocol and requires no mining. Also, Ripple Labs' distribution of the original limited amount of XRP currency has met with a fair amount of controversy, and in particular the founders' retainment of 20% is seen as a high percentage.
However, Esquire countered in 2013 that "if that is devious, then so is every company that's ever gone public while retaining the great bulk of its shares." Much of the controversy was settled after the announcement that the founders Jed McCaleb and Arthur Britto would be selling their XRP at a mediated rate over several years, "a move that should add stability and restore confidence to the XRP market." CEO Chris Larsen in turn donated 7 billion XRP to the Ripple Foundation for Financial Innovation, with the XRP to be "locked up" and donated over time. In 2016, of the 20% allocated initially to the founders, nearly half had been donated to non-profits and charities.
Ripple has also been criticized for not being truly decentralized, or for using only a few core validation nodes for transaction consensus, compared to Bitcoin and Ethereum in the five digits. Bitcoin developer Peter Todd notes, "..Ripple's technical documentation doesn't make any of these risks clear – nowhere do they describe in detail how nodes can fall out of consensus with one another if their UNLs (Unique Node List) don't match."
Bigger Block Size (2 to 8 MB) & Hard Fork
Some members of the bitcoin community felt that adopting BIP 91 without increasing the block-size limit favored people who wanted to treat bitcoin as a digital investment rather than as a transactional currency.
The plan to do a hard fork was first announced by Bitmain. The project was originally referred to as UAHF: A contingency plan against UASF (BIP148) by Bitmain on their corporate blog, which the ASIC bitcoin mininghardware manufacturer would launch if BIP 148 (a User Activated Soft Fork) succeeded. Subsequently, developers took interest in the project. The Bitcoin Cash name was originally proposed by Chinese mining poolViaBTC.
A stated goal of the fork was to increase the number of transactions its ledger can process by increasing the block size limit to eight megabytes from two. CoinDesk said that these motivations might have been behind the development and launch of Bitcoin Cash:
• Some users wanted an increase in bitcoin's block size limit parameter
• SegWit was likely to activate and some users wanted to avoid the feature
• The likelihood that SegWit2x would not launch in 2017
Layered network & not Perfect
Dash (formerly known as Darkcoin and XCoin) is an open source peer-to-peer cryptocurrency. On top of Bitcoin's feature set, it currently offers instant transactions (InstantSend), private transactions (PrivateSend) and operates a self-governing and self-funding model that enables the Dash network to pay individuals and businesses to perform work that adds value to the network. Dash's decentralized governance and budgeting system makes it a decentralized autonomous organization (DAO). Within the first two days of launch, 1.9 million coins were mined, which is approximately 10% of the total supply that will ever be issued. Creator and lead developer of Dash, Evan Duffield, attributed this to a bug created when the Litecoin code was forked to create Dash, "which incorrectly converted the difficulty, then tried using a corrupt value to calculate the subsidy" Once the problem was resolved, Evan offered to relaunch the coin, but the community overwhelmingly disapproved. He suggested an "airdrop" of coins in order to broaden the initial distribution but the community also disapproved of this proposal. As such, the initial distribution was left alone and development of the project continued. The majority of mined coins were distributed on cryptocurrency exchanges in the following months at very low price levels.
Unlike Bitcoin's single-tier network, where all jobs on the network are performed by miners, Dash utilizes a two-tier network. Certain network functions, such as creating new blocks, are handled by the miners. The second tier of the Dash network consists of "masternodes" which perform PrivateSend, InstantSend, and governance functions.
Masternodes require 1000 DASH as collateral to prevent sybil attacks. That collateral can be spent at any time, but doing so removes the associated masternode from the network. Because masternodes provide vital network functions, the block reward is split between miners and masternodes, with each group earning 45% of the block reward. The remaining 10% of each block reward funds the "budget" or "treasury" system.
Masternode distribution worldwide, excluding IPv6 and Tor nodes (as of March 2017).
PrivateSend is a coin-mixing service based on CoinJoin, with numerous modifications. These include using masternodes instead of a single website, chaining by mixing with multiple masternodes, restricting the mixing to only accept certain denominations (e.g.: 0.01 DASH, 0.1 DASH, 1 DASH, and 10 DASH, etc.), and passive mode. The maximum allowed for a PrivateSend transaction is 1000 DASH.
Later iterations used a more advanced method of pre-mixing denominations built into the user's cryptocurrency wallet. The implementation of PrivateSend also allows masternodes to submit the transactions using special network code called DSTX, this provides additional privacy to users due to the deadchange issue present in other CoinJoin based implementations such as DarkWallet and CoinShuffle. In June 2016, DarkSend was rebranded to PrivateSend.
In its current implementation it adds privacy to transactions by combining identical inputs from multiple users into a single transaction with several outputs. Due to the identical inputs, transactions usually cannot be directly traced, obfuscating the flow of funds. PrivateSend makes Dash "fungible" by mixing the coins in the same denomination with other wallets, ensuring that all coins are of the same value.
InstantSend is a service that allows for near-instant transactions. Through this system, inputs can be locked to specific transactions and verified by consensus of the masternode network. Conflicting transactions and blocks are rejected. If a consensus cannot be reached, validation of the transaction occurs through standard block confirmation. InstantSend solves the double-spending problem without the longer confirmation times of other cryptocurriencies such as Bitcoin.
In June 2016, InstantX was rebranded to InstantSend.
♦ Governance and funding
Dash is the first decentralized autonomous organization powered by a Sybil proof decentralized governance and funding system. Decentralized Governance by Blockchain (DGBB), often referred to simply as the "treasury system" is a means of coming to consensus on proposed network changes and funding development of the Dash ecosystem. Ten percent of the block rewards go to this "treasury" in order to pay for projects that benefit Dash. Funding from the treasury system has been used to hire additional developers and other employees, to fund attendance at conferences, and to fund integrations with major exchanges and API providers.
Each masternode operator receives one vote. Proposals are eligible for funding according to the following formula: (YES VOTES - NO VOTES) > (TOTAL NUMBER OF MASTERNODES * 0.1). If there are more proposals that meet that criterion than there are budget funds for the month, then the proposals with the highest number of net votes will be paid. Community interaction with proposal submitters is done through the dash.org forums, or through community-driven websites, like DashCentral. These websites allow proposal submitters to provide multiple drafts, then lobby for community support before finally submitting their project to the network for a vote. After the submitter has enough support, the network will automatically pay out the required funds in the next super block, which happens monthly.
The funding system has seen revenue growth. In September 2015, the treasury system provided $14,000 in funding per month. Due to increases in the value of Dash, as of March 2017 the treasury system provided about $574,000 per month in funding. The treasury system has created a positive feedback loop, whereby additional development increases the value of Dash, which increases the amount of funding provided by the budget system.
4*Bitcoin for everything & Easier Mining
Litecoin was released via an open-source client on GitHub on October 7, 2011 by Charlie Lee, a former Google employee. The Litecoin network went live on October 13, 2011. It was a fork of the Bitcoin Core client, differing primarily by having a decreased block generation time (2.5 minutes), increased maximum number of coins, different hashing algorithm (scrypt, instead of SHA-256), and a slightly modified GUI.
During the month of November 2013, the aggregate value of Litecoin experienced massive growth which included a 100% leap within 24 hours.
Litecoin reached a $1 billion market capitalization in November 2013. By late November 2017, its market capitalization was US$4,600,081,733 ($85.18 per coin). By mid-December 2017, the coin's marketcap had reached US$20,000,000,000 and each litecoin was valued at approximately US$371.00.
In May 2017, Litecoin became the first of the top 5 (by market cap) cryptocurrencies to adopt Segregated Witness. Later in May of the same year, the first Lightning Network transaction was completed through Litecoin, transferring 0.00000001 LTC from Zürich to San Francisco in under one second.
♦ Differences from Bitcoin
Litecoin is different in some ways from Bitcoin.
• Supply limit is 84 million, four time of the Bitcoin.
• The Litecoin Network aims to process a block every 2.5 minutes, rather than Bitcoin's 10 minutes. The developers claim that this allows Litecoin to have faster transaction confirmation.
• Litecoin uses scrypt in its proof-of-work algorithm, a sequential memory-hard function requiring asymptotically more memory than an algorithm which is not memory-hard. Due to Litecoin's use of the scrypt algorithm, FPGA and ASIC devices made for mining Litecoin are more complicated to create and more expensive to produce than they are for Bitcoin, which uses SHA-256.