Blockchain creates a shared system of record among business network members, eliminating the need to reconcile disparate ledgers.It's permissioned
Each member of the network must have access privileges. Information is shared only on a need-to-know basis.It's immutable
Consensus is required from all members and all validated transactions are permanently recorded. Even a system administrator can't delete a transaction.
Self-operating computer program that automatically executes when specific conditions are met. Because smart contracts run on the blockchain, they run exactly as programmed without any possibility of censorship, downtime, fraud or third party interference.
Ethereum's purpose is to offer and run decentralized smart-contract applications powered by blockchain technology that do not go offline and cannot be altered. It provides users with aEthereum uses smart contracts. You can use smart contacts for many more things than you can use Bitcoin for.
The Ethereum's blockchain was released in 2015. It is 6 years newer and further developed compared to the Bitcoin blockchain (released in 2009). Ethereum's blockchain is a further advanced version of Bitcoin's blockchain. It fixes some of its issues and introduces new features such as smart contracts.
Ethereum's purpose is to offer and run decentralized smart-contract applications powered by blockchain technology that do not go offline and cannot be altered. It provides users with aEthereum uses smart contracts. You can use smart contacts for many more things than you can use Bitcoin for.When to use Ethereum based Smart Contract
Ethereum also has a built in cryptocurrency (eth) and thus can be a very good match for applications that need this inbuilt. However, this could also be a disadvantage as there are several use cases where the cryptocurrency is not really needed.Ethereum runs the Smart Contracts on the EVM for applications that are attributed to being decentralized and are for mass consumption.
On the other hand, Hyperledger leverages blockchain technology for business. It is designed to support pluggable implementations of components delivering high degrees of confidentiality, resilience and scalability. Hyperledger has a modular architecture and provides a lot of flexibility in how you want to use it. Its extensible architecture provides futuristic solutions for enterprise blockchains.
IPFS uses a content addressing method compared to IP addressing method used by HTTP. Using content address fetches the data faster as it will retrieve the data from the closest system which has a copy of it. Since it is content addressed you might ask, how does IPFS differentiate the webpages? It does so by generating a unique address for each page. The content is identified by a cryptographically generated hash which cannot be changed.
IPFS uses a Distributed Hash Table to store the data on various systems. An example of DHT is Chord. To have control over the DHT and give structure to it, IPFS uses the Merkle DAG protocol inspired by git. Git uses this protocol for version control whereas IPFS uses it for providing a structure. Another advantage of IPFS is that the user can download parts of a file from various sources at once and combine it at their side rather than downloading the whole file from a single source.
Interesting Fact: The reason it was named Interplanetary File system is because, when humans become a interplanetary species, it would be sensible to fetch the data from the closest user than from planets light years away
Hadoop Security Architecture Overview
Security in Hadoop is defined by 5 pillars:
Administration Centrally Managed and consistent Security
Authentication Authenticate users and systems
Authorization Provision access to data
Audit Maintain record of data access
Data Protection Protect data at rest and in motion