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Basics of Blockchain Architecture
Published in Latesh Malik, Sandhya Arora, Urmila Shrawankar, Vivek Deshpande, Blockchain for Smart Systems, 2022
We now move on to consensus in permissioned scenarios. In a permissioned network, where members know each other and have earned a membership in the network, Proof of Authority (POA) consensus is used. Selected nodes perform the role of validators and have their reputation at stake. For example, in a national level banking blockchain, the main regulatory bank can maintain the Validator nodes. The selected consensus members are known to be reputable and are expected to take full responsibility of the transactions approved for inclusion. Validators of POA usually run multiple nodes to ensure redundancy. There may be more than one validator and it is expected that they exercise their authority in rejecting any malicious transactions approved by other validators. POA is usually recommended for permissioned networks, as it brings about a certain degree of centralization which is permissible in private or consortium networks such as supply chains, banking or trade finance networks, etc. POA gives a higher throughput as lesser number of parties participate in consensus. For example: Ethereum Proof of Authority on Azure [19] offering and VeChain, which is a blockchain platform designed to enhance supply chain management and business processes, use POA.
Building Permissioned Blockchain Networks Using Hyperledger Fabric
Published in Sandeep Kumar Panda, Ahmed A. Elngar, Valentina Emilia Balas, Mohammed Kayed, Bitcoin and Blockchain, 2020
K. Varaprasada Rao, Mutyala Sree Teja, P. Praneeth Reddy, S. Saikrishna
Ethereum [3,5], which is known as the most popular Blockchain platform after Bitcoin, is a decentralized platform that allows the creation of blockchain-based DApps (decentralized applications) using Ethereum smart contracts. Smart contracts [6] are self-executing digital contracts, which execute precisely as planned without any chance of lay-off, fraud, or intervention from third parties. Ethereum provides both public and permissioned configurations. Ethereum’s main network [3,5] is an open blockchain network where anyone can enter the network and take part in the process of mining. As Ethereum also offers private blockchain configuration, it uses PoA (Proof of Authority) as a consensus mechanism. PoA doesn’t need mining process, it requires only few authority nodes to achieve consensus. Hence, Ethereum does provide an option of private network but it doesn’t offer a complete permissioned configuration required for an industry-level application.
An Overview of Blockchain and its Applications in the Modern Digital Age
Published in Sudhir Kumar Sharma, Bharat Bhushan, Bhuvan Unhelkar, Security and Trust Issues in Internet of Things, 2020
Reinaldo Padilha França, Ana Carolina Borges Monteiro, Rangel Arthur, Yuzo Iano
This is how dPoW (delayed PoW) exists which uses the hash rate of another blockchain to promote the second layer of protection for a given blockchain. The dPoS (delegated PoS) allows participants to elect a representative to ensure the security of the network. The PoA (proof of authority) causes transactions to be validated by approved accounts. Proof of reputation, which depends on the reputation of the participants to keep the network safe, is similar to PoA, causing the network to penalize participants who try to attack it. Several other consensus algorithms are being used and developed with the focus on increasing the security of virtual currency transactions [32].
Blockchain for supply chain quality management: challenges and opportunities in context of open manufacturing and industrial internet of things
Published in International Journal of Computer Integrated Manufacturing, 2020
Jinying Li, Ananda Maiti, Matthew Springer, Tony Gray
The second type of blockchain is more about record-keeping. This type of blockchain use Proof of Authority (PoA) or similar mechanisms to achieve consensus and enter data into the blockchain. The most common example of this is Hyperledger Fabric (HF) (Androulaki et al. 2018b). HF is designed for business-to-business blockchain operation. HF focuses on the fundamental aspects of business such as privacy and speed while providing the typical advantage of the blockchain i.e. immutability of data in the blockchain. The trade-off for this that Hyperledger Fabric requires the participating organizations to be at least known to each other. They must each authorize and recognize others in the blockchain system. Typically, this is done by using digital certificates among the peer nodes in the blockchain.