As described in the permissions management page, there are eight types of permissions in MultiChain blockchains. Three of these (connect, send and receive) can be considered as low risk users who obtain them can only connect to the blockchain and transact on their own behalf. Three more (issue, create and activate) are medium risk, because users who obtain them can respectively issue assets, create streams, and manage other users low risk permissions. Two final permissions (mine and admin) can be considered as high risk nodes with mine permissions participate in the consensus algorithm, while those with admin permissions can modify all other permissions for users. The purpose of a blockchain is to create decentralized databases, which are not under the control of any individual party. Therefore it is natural and necessary to extend this philosophy to the administration of permissions. For all medium risk and high risk permissions, a MultiChain blockchain can be configured so that individual administrators are unable to change those permissions on their own. Instead, a certain proportion of the administrators have to agree before the permissions change takes place, with the proportions defined by the admin-consensus-* blockchain parameters . This tutorial requires MultiChain 1.0 alpha 27 or later, installed on Linux. Although in reality multiple administrators would be spread across multiple organizations (and therefore nodes), we can simulate the process by creating multiple addresses on a single node, and using the grantfrom command to control which address performs each permissions change. We will start by creating a new blockchain from the command line, with specific values for certain blockchain parameters, then launching the chain and entering interactive command Continue reading >>
What Is The Difference Between Public And Permissioned Blockchains?
Join 4,500+ attendees at Consensus 2018. Register Now! What is the Difference Between Public and Permissioned Blockchains? In our guide "How Does Blockchain Technology Work?" ,we introduced a description of the three technologies that make up blockchain technology:cryptographic keys, a distributed network and a network servicing protocol. Bitcoin is the most ambitious kind of blockchain. Anyone can use bitcoin's cryptographic keys, anyone can be a node and join the network, and anyone can become a miner toservice the network and seek a reward. Miners can walk away from being a node, return if and when they feel like it, and get a full account of all network activity since they left. Basically, anyone can read the chain, anyone can make legitimate changes and anyone can write a new block into the chain (as long as they follow the rules). Bitcoin is totally decentralized. It is also described as a 'censor-proof' blockchain. For these reasons, it's known by its widest description, a public blockchain. But, this is not the only way to build a blockchain. Blockchains can be built that require permission to read the information on the blockchain, that limit the parties who can transact on the blockchain and that set who can serve the network by writing new blocks into the chain. For example, Ripple runs a permissioned blockchain. The startup determines who may act as transaction validator on their network, and it has included CGI, MIT and Microsoft as transaction validators, while also building its own nodes in different locations around the world. A blockchain developer may choose to make the system of record available for everyone to read, but they may not wish to allow anyone to be a node, serving the network's security, transaction verification or mining. It's a mix-and- Continue reading >>
The Trust Trade-off: Permissioned Vs Permissionless Blockchains
The Trust Trade-Off: Permissioned vs Permissionless Blockchains By Devon Allaby, Business Designer at Fjord Australia. As the media frenzy surrounding Bitcoin fades from the front page, the enthusiasm for Blockchain has remained stalwart. However, the transition from Blockchain as a conceptual topic to a technology with a solid developer community and production ready deployments has given birth to some interesting design debates one of which is the permissionless vs the permissioned Blockchain model. If youve heard people talking about Blockchain in a general sense, most likely they were talking about a permissionless Blockchain. This model is what general public are familiar with because the most famous Blockchain projects (Bitcoin and Ethereum) are permissionless Blockchains meaning that anybody can create an address and begin interacting with the network. The other reason this model is the more widely discussed of the two is because the characteristics of a permissionless Blockchain (decentralised, anonymous and equally accessible to anyone with a computer) are the characteristics that aligned remarkably with political movements that began to gain serious ground after the Global Financial Crisis in 2008. In contrast, the permissioned Blockchain is a closed and monitored ecosystem where the access of each participant is well defined and differentiated based on role. They are built for purpose, establishing rules for transaction that align with the needs of an organisation or a consortium of organisations. The permissioned Blockchain isnt looking to overthrow the political system, or remove the need for established financial institutions. Instead it leverages some of the other core elements of Blockchain architecture (immutability, ability to grant granular permissio Continue reading >>
The Difference Between Public And Private Blockchain
Blockchain Unleashed: IBM Blockchain Blog The difference between public and private blockchain May 31, 2017 | Written by: Praveen Jayachandran Categorized: Blockchain Developers | Blockchain Explained | Blockchain Identity There are a number of explanations on what blockchain is and what exactly is the difference between Bitcoin and blockchain , but another area where I get many questions, is the difference between public and private blockchain. The similarities of public and private blockchain Many flavors of blockchain have evolved over the years and the terminology is often misconstrued. This is easy to do because public and private blockchain have many similarities: Both are decentralized peer-to-peer networks, where each participant maintains a replica of a shared append-only ledger of digitally signed transactions. Both maintain the replicas in sync through a protocol referred to as consensus. Both provide certain guarantees on the immutability of the ledger, even when some participants are faulty or malicious. The sole distinction between public and private blockchain is related to who is allowed to participate in the network, execute the consensus protocol and maintain the shared ledger. A public blockchain network is completely open and anyone can join and participate in the network. The network typically has an incentivizing mechanism to encourage more participants to join the network. Bitcoin is one of the largest public blockchain networks in production today. One of the drawbacks of a public blockchain is the substantial amount of computational power that is necessary to maintain a distributed ledger at a large scale. More specifically, to achieve consensus, each node in a network must solve a complex, resource-intensive cryptographic problem called a proo Continue reading >>
Blockchain What Is Permissioned Vspermissionless?
Blockchain What is Permissioned vsPermissionless? If you have been following distributed ledger technologies (Blockchain), you would see the term permissionedblockchain being thrown around. What is the core difference between a permissionedvs. a permissionless blockchain? A permissionedblockchain restricts the actors who can contribute to the consensus of the system state. In a permissionedblockchain, only a restricted set of users have the rights to validate the block transactions. A permissionedblockchain may also restrict access to approved actors who can create smart contracts. Permissionless blockchain is contrary to what you read above Here anyone can join the network, participate in the process of block verification to create consensus and also create smart contracts. A good example of permissionless blockchain is the Bitcoin and Ethereum blockchains, where any user can join the network and start mining. Now you may wonder what the benefits and disadvantages of each approach are? In a permissionless world, you do not have to prove your identity to the ledger. As long as you are willing to commit processing power to be part of the network and extending the blockchain, you are allowed to play. Any miner who is playing the game by the rule may be able to solve the hash puzzle and verify the block of transactions to win the mining reward (Higher the mining power, better the chances of winning the mining reward). In the permissionedblockchain world, you need to be an approved actor in the system to participate in growing the chain as well as building consensus. Many of the blockchain consortiums that build private blockchains for financial institutions and other enterprises follow this model. One other critical difference between these two is the underlying mining mo Continue reading >>
Hashgraph Wants To Give You The Benefits Of Blockchain Without The Limitations
The spotlight on the distributed ledger space to-date is primarily focused on blockchain . Yet, blockchains come with limitations by design. Consensus mechanisms using proof of work (POW) are by their nature slow, so the community can come to agreement and throw away the blocks they dont agree on. This design also includes inherent inefficiencies such as electricity consumption discarded on stale blocks. Distributed ledger technologies envision a new, better peer-to-peer compute model that could help us harness compute power like never before. As we move away from the client-server compute model, we move closer to realizing a new trust layer for the internet. This transition is still limited by challenging problems yet to be solved around efficiency, scalability, and interoperability. The hashgraph algorithm, invented by Leemon Baird , the co-founder and CTO of Swirlds, is a consensus mechanism based on a virtual voting algorithm combined with the gossip protocol to achieve consensus quickly, fairly, efficiently, and securely. Today, the founders of Swirlds , a permission-based ledger that uses the hashgraph consensus mechanism, launched the Hedera Hashgraph Platform, a separate venture dedicated to developing a public ledger based on the hashgraph. Hashgraph is an alternative to blockchain a first generation tech with severe constraints in terms of speed, fairness, cost, and security, explained Mance Harmon, Co-founder of Swirlds and Hedera. A fundamental bottleneck has been the performance how many applications are there that can run on a database that can just do 5 transactions per seconds. Hashgraph aims to provide the benefits of blockchain as a distributed ledger technology without the limitations. While many ledgers use the gossip protocol, Baird combined the go Continue reading >>
Ethereum: Permission, Access, And Consensus? Better Thanbitcoin?
enjoys learning about blockchain technology. Ethereum: Permission, Access, and Consensus? Better thanBitcoin? Due to several challenges in the Bitcoin blockchain protocol related to the limited capabilities of its scripting language, second generation blockchain ledgers such as Ethereum implement their own version of a decentralized ledger. The Ethereum blockchain has an underlying goal similar to the Bitcoin blockchains, which is to facilitate transactions between consenting individuals who would otherwise have no means to trust each other Wood 2016 It does so by establishing a transaction-based state-machine in which participants can expect that agreements between them will be enforced autonomously. In order to do so, Ethereum provides a quasi-Turing-complete virtual state machine, the Ethereum Virtual Machine (EVM). It allows developers to deploy complex smart contracts that are compiled in this machine and autonomously enforce agreements when the programmed conditions are met. This possibility is one of the fundamental differences to the Bitcoin blockchain. In the following posts, the blockchain characteristics defined in the post Bitcoin, Ethereum, and Hyperledger Fabric Which one wins? will be assessed for the Ethereum blockchain. To remain digestible, the first three of the eight characteristics will be explained here, namely: Permission, Access, and Consensus. With respect to permissioning, Ethereum is a public, permissionless blockchain. This means, everyone can download an Ethereum client, view the transaction data and participate in transaction validation (mining). Permissioning is however possible on higher development layers, namely on the application layer. Some groups, mostly industry consortia, have adapted Ethereums open-source protocol to run their ow Continue reading >>
Types Of Blockchains
Blockchains & Distributed Ledger Technologies The Bitcoin White Paper was published by Satoshi Nakamoto in 2008; the first Bitcoin block got mined in 2009. Since the Bitcoin protocol is open source, anyone could take the protocol, fork it (modify the code), and start their own version of P2P money. Many so-called altcoins emerged and tried to be a better, faster or more anonymous than Bitcoin. Soon the code was not only altered to create better cryptocurrencies, but some projects also tried to alter the idea ofblockchain beyond the use case of P2P money. The idea emerged that the Bitcoin blockchain could be in fact used for any kind of value transaction or any kind of agreement such as P2P insurance, P2P energy trading, P2P ride sharing, etc. Colored Coins and Mastercoin tried to solvethat problem based on the Bitcoin Blockchain Protocol. TheEthereum project decided to create their own blockchain, with very different properties than Bitcoin, decoupling the smart contract layer from the core blockchain protocol, offering a radical new way to create online markets and programmable transactions known as Smart Contracts . Private institutions like banks realized that they could use the core idea of blockchain as a distributed ledger technology (DLT), and create a permissionedblockchain (privateor federated), where the validator is a member of aconsortium or separate legal entities of the same organization. The term blockchain in the context of permissioned privateledger is highly controversial and disputed. This is why the term distributed ledger technologies emerged as a more general term. Private blockchains are valuable for solving efficiency, security and fraud problems within traditional financial institutions, but only incrementally. Its not very likely that private Continue reading >>
Blockchain - How To Implement Role-based Access Control To User's Private Data? - Ethereum Stack Exchange
How to implement role-based access control to user's private data? We have this application scenario and try to see if Ethereum, or blockchain in general, is a good solution for this. The basic idea is the user controls a small amount of private sensitive data (e.g., individual profile change history, transaction history). The user can control who has access to that data. When user A toggles on the access for another user B, B can see the whole transaction history. Obviously other users without access shouldn't see A's data. We are thinking of storing user's encrypted data in the public blockchain. Ethereum is one of the options we are considering. The advantages of doing so is: Any user with access see the un-alterable transaction trail (good for auditing purpose) How would you implement the role based access control to the content encryption key? Obviously we can't encrypt the content with the user's own private key, otherwise when user wants to share data, he/she would have to give away the private key in order to decrypt the content. So each unit of private data should have a unique encryption key. And we have to change the encryption key and re-encrypt the content every time the user revokes someone else's access. Where should we store these encryption keys? Should we store them in a privately owned database? A more general question is, since blockchain achieves tracking the ownership in a public shared ledger, can it implement role-based access control completely with everything (except user's private keys) in public chain as well? Thanks for the answer of Rob Hitchens. I read Vitalik's blog post and found that it's difficult to implement obfuscated computing on chain. So it's impossible to store everything on the public chain while keeping user's data privacy. T Continue reading >>
17 Blockchain Platformsa Brief Introduction
17 blockchain platforms a brief introduction Blockchain technology was announced through the paper titled Bitcoin: A Peer-to-Peer Electronic Cash System by Satoshi Nakamoto in 2008. Interestingly, this paper does not specifically use the word blockchain. This paper talks about a purely peer-to-peer version of electronic cash where the network timestamps transactions by hashing them into an ongoing chain of hash-based proof-of-work, forming a record that cannot be changed without redoing the proof-of- work. The open source PT-BSC (Blockchain Security Controls) defines a blockchain as a peer-to-peer network which timestamps records by hashing them into an ongoing chain of hash-based proof-of-work, forming a record that cannot be changed without redoing the proof-of-work. A blockchain can be permissioned, permission-less or hybrid. On the other hand, a distributed ledger is defined as a peer-to-peer network, which uses a defined consensus mechanism to prevent modification of an ordered series of time-stamped records. Consensus mechanisms include Proof of stake, Federated Byzantine Agreement etc. The more popular blockchain / distributed ledger systems in alphabetical order are: BigChainDB, an open source system that starts with a big data distributed database and then adds blockchain characteristics decentralized control, immutability and the transfer of digital assets. Chain Core, a blockchain platform for issuing and transferring financial assets on a permissioned blockchain infrastructure. Corda, a distributed ledger platform with pluggable consensus. Credits, a development framework for building permissioned distributed ledgers. Domus Tower Blockchain, designed for regulated environments, benchmarked at ingesting over 1 million transactions per second. Elements Blockc Continue reading >>
Banks Claim They're Building Blockchains. They're Not
Banks Claim They're Building Blockchains. They're Not By David Floyd | Updated February 23, 2018 11:54 AM EST Even after bitcoin gained some name recognition as nerd money, as a lubricant for dark web commerce, as a latter-day Semper Augustus its technological underpinnings remained obscure to all but the most dedicated cryptoheads. As far as the media was concerned, Nefarious Ross Ulbricht and Mysterious SatoshiNakamoto were the story, not some programmingminutiae whirring in the background. By mid-2015, though, the blockchain was getting noticed. Recode ran the headline "Forget Bitcoin What Is the Blockchain and Why Should You Care?" Bloomberg Markets, "It's All About the Blockchain." The Economist wasn't about to be left out . Before the year was out it was obvious to anyone in the know: bitcoin was a sideshow, a raving 4chananarchistin a Guy Fawkes mask. The main attraction was this mighty engine of certainty, the blockchain . At some point, unfortunately,blockchain hype outstripped analysis. What exactly is this "technology behind bitcoin" that banks, governments and a generation of next-big-thing seeking MBA grads are piling into? Are we all talking about the same thing, or are some of these blockchain-mongers usingthe buzzword of the year to sell oldtech? (See also, Blockchain: The Backbone of Finance's Entire Future .) The Rise of the "Permissioned Blockchain" Bitcoin's blockchain, a form of distributed ledger technology , allows thousands of people who do not know or trust each other to transact with one another. Normally such a network requires a trusted intermediary to keep bad actors from spending their funds twice or laying claim to money that isn't theirs. Not so with bitcoin. Through clever cryptography, bitcoin's proof of work system allows an arbitrary Continue reading >>
On Public And Private Blockchains
Over the last year the concept of private blockchains has become very popular in the broader blockchain technology discussion. Essentially, instead of having a fully public and uncontrolled network and state machine secured by cryptoeconomics (eg. proof of work, proof of stake), it is also possible to create a system where access permissions are more tightly controlled, with rights to modify or even read the blockchain state restricted to a few users, while still maintaining many kinds of partial guarantees of authenticity and decentralization that blockchains provide. Such systems have been a primary focus of interest from financial institutions, and have in part led to a backlash from those who see such developments as either compromising the whole point of decentralization or being a desperate act of dinosaurish middlemen trying to stay relevant (or simply committing the crime of using a blockchain other than Bitcoin ). However, for those who are in this fight simply because they want to figure out how to best serve humanity, or even pursue the more modest goal of serving their customers, what are the practical differences between the two styles? First, what exactly are the options at hand? To summarize, there are generally three categories of blockchain-like database applications: Public blockchains: a public blockchain is a blockchain that anyone in the world can read, anyone in the world can send transactions to and expect to see them included if they are valid, and anyone in the world can participate in the consensus process the process for determining what blocks get added to the chain and what the current state is. As a substitute for centralized or quasi-centralized trust, public blockchains are secured by cryptoeconomics the combination of economic incentive Continue reading >>
Permissioned Blockchain Or Permission-less Blockchain What Can Make Your Blockchain Business Successful?
Permissioned Blockchain or Permission-less Blockchain What can make your Blockchain Business successful? Blockchain and Business Enthusiast |President - Students' Council of NMCCE|Speaker|Company Guru at BBN Times|Assurance Till now, we have read about this ground-breaking technology called Blockchain and smart contracts that has the potential to disrupt industries across the globe, in my previous articles. Recently, companies like Kodak and Reliance(India) and countries like Venezuela and Dubai have put up their plans to introduce crypto currencies in their respective companies/countries. Kodak witnessed a 220% surge in it's share price! Seeing the early adoptions and implementations, it is very natural for us to think of implementing Blockchain into our businesses. But before we actually do it, we need to ask ourselves some prime questions Will blockchain bring value to my kind of enterprise, business or the industry that I work in? How will my business scale if there are no takers of crypto token that I made? How can crypto currencies and smart contracts be integrated with our mainstream businesses through the Blockchain API? Will my blockchain business be able to beat the traditional digital Internet of Things (IoT) business models? These questions need to be answered before you adopt Blockchain. Coming down to the very basics, a business works only when there are customers for its products or services. And we all know, customers will always want value in terms of quality of the product or service for which they are paying their hard-earned money. So how do we evaluate and approach Blockchains implementation? The most important thing you should know about are the types of Blockchain. There are currently two types of Blockchain that can be implemented depending on y Continue reading >>
Monax | Explainer | Permissioned Blockchains
What is a Permissioned Blockchain Network? The DNA of a permissioned blockchain network is no different than the DNA of an unpermissioned blockchain network. With the exception of one gene that has been mutated. Properly permissioned blockchain networks differ from unpermissioned blockchain networks solely based on the presence (or absence) of an access control layer built into the blockchain nodes. The first primary difference between a properly conceived permissioned blockchain network and an unpermissioned blockchain network is whether the participants in the network have an ability to restrict who can participate in the consensus mechanism of the blockchains network. Permissioned blockchain networks allow the network to appoint a group of participants in the network who are given the express authority to provide the validation of blocks of transactions. Or, to participate in the consensus mechanism. The second primary difference between a properly conceived permissioned blockchain network and an unpermissioned blockchain network is whether the participants in the network have an ability to restrict who can create smart contracts (if the blockchain node is logic optimized ) and/or transact on the blockchain network. Together, at Monax, we call these capabilities based permissions. The Benefits of Permissioned Blockchain Networks To understand the benefits of permissioned blockchain networks to their participants, we must consider the relative advantages which they have vis a vis their unpermissioned cousins. We must also consider the relative advantages which permissioned blockchain networks have vis a vis their cousins on the other side of the spectrum: hub and spoke distributed databases. Permissioned Blockchain Networks are More Performant Than Unpermissioned Blo Continue reading >>
How To Choose Between Public And Permissioned Blockchain For Yourproject
How To Choose Between Public And Permissioned Blockchain For YourProject If your company is considering creating a project on blockchain, you have two options: working on a public or a permissioned blockchain. The difference between the two is similar to the public and private cloud service. One of them is open to anyone using a certain platform. The other is only available to a select group with permission to use it. To compare, think of your companys email over VPN versus Gmail. The public blockchain is Gmail anyone can sign up and access those services. A permissioned blockchain is a similar to a VPNonly a select group, given access by the company, can use the company email. Third parties are unable to use it, and they have to get approval to join. Still not sure which to choose? Heres how to decide between the two: You probably recognize the most popular public blockchains Bitcoin, Ethereum, and Ripple. Use a public blockchain if you want to involve the general population in your business. Anyone in the world can access a public blockchain to create transactions. And most public blockchains use a consensus mechanism called proof of work a statement proving youve done the work for confirming the transaction and adding it to the blockchain. Imagine I send you one bitcoin in a transaction. That transaction goes to a network of millions of nodes. Somewhere, a bitcoin miner confirms the transaction by solving a mathematical puzzle. They were the fastest to solve it, so they win the right to add the transaction to the blockchain. They record the transaction and their proof of work to get paid a commission, which they earn in bitcoin. This is how standard public blockchains work. But the more your network grows, the more nodes you have in the system. The bigger the networ Continue reading >>