Overview 

Bitcoin is in its eighth year. This period seems like an eternity in IT standards but the Blockchain, the Bitcoin underlying technology, is only at its nascent stage. There is no month  passing without an announcement from a startup or a some innovation Lab claiming creating the “Blockchain Platform” that will overcome some or all the Bitcoin limitations.  Each company that want to build the next Blockchain-based application, must pick the right Blockchain Platform to build upon unless it is also interested on some low level cryptographic stuff which i don’t see any business value to it.  This page focuses on scoping some existing platforms specifically for developing new Blockchain-based applications.   

Blockchain Features

In assessing opportunities to evaluate the different platforms that can be suitable for potential use cases, it is helpful to have an understanding of the core Blockchain features that makes it so unique.  Five key features that when combined, can create innovative platforms that will talk about later in this paper:   

Public vs Private Blockchain 

A public blockchain is a blockchain, in which there are no restrictions on reading blockchain data (which still may be encrypted) and submitting transactions for inclusion into the blockchain.

A private blockchain is a blockchain, in which direct access to blockchain data and submitting transactions is limited to a predefined list of entities.   

Permissionless vs Permissioned Blockchain 

A permissionless blockchain is a blockchain, in which there are no restrictions on identities of transaction processors (validators that are eligible to create blocks of transactions).

A permissioned blockchain is a blockchain, in which transaction processing is performed by a predefined list of entities with known identities (example Banks). Permissioned blockchains are attractive in cases, where transaction-processing nodes need to be known to comply with regulations, as in the case of financial institutions. 

                                                Source: http://bitfury.com/content/5-white-papers-research/public-vs-private-pt1-1.pdf     

Blockchain Native Token 

A unit of value that can be earned and used to create transactions on the system. If this token serves as currency in the system, we talk about cryptocurrency (like Bitcoin).  These Tokens don’t exist as string literals but rather they exist conceptually as entries on a ledger (a blockchain). You can make transactions with the tokens that you own, only if you have a key (Private Key) that lets you create a new entry on the Blockchain. In most Blockchain Platforms, tokens are used as transaction spam prevention mechanism (if all transactions cost some token, it limits the ability to spam); they are used also to incentivize Validator nodes (nodes that validate the state of the blockchain).  Some private/permissioned Blockchains are tokenless as the underlying peer to peer network is deployed in a controlled manner. 

Consensus protocol 

Due to the distributed nature of the Blockchain structure, the underlying peer-to-peer network needs a consensus protocol to validate and agree on a new version of the ledger allowing the settling of transactions by incorporating them on the ever-growing chain of blocks.  Bitcoin come-up with a pretty genius protocol (Proof-Of-Work) which works perfectly for Bitcoin, but showed limits when applied to other domains. Therefore, proof-of-xx protocol suite appeared to accommodate different use cases (proof-of-stake, proof-of-burn, proof-of-activity ...)   

Mining

Mining is the process by which some special nodes (validators) on the peer-to-peer network get incentivized when validating blocks on the Blockchain. The incentive is the creation of a limited amount of the blockchain Native Token. In public blockchains, Mining is a central piece.   

Blockchain Platforms

Giving the huge number of Blockchain platforms available, we picked a representative sample covering most of the possible use cases.  All studied platforms fall into five categories:

Bitcoin blockchain/Non-bitcoin currency Platforms

These platforms leverage on the network-effect of the Bitcoin Blockchain to build customized services on top of it. Services are built by adding metadata to Bitcoin transactions.   

Financial Services oriented Blockchain Platforms 

Platforms that target specific FS use cases (Payment, Exchange, Remittances ...) generally geared toward transaction-based operating model.   

General purpose Blockchain Platforms 

Platforms geared toward more complex business-logic schemes. Supports Smart contract executions on the Blockchain. Smart contracts are contracts that do not require human interpretation or intervention to complete. Their settlement is done entirely by running a computer program. Smart contracts are code-based contracts, as opposed to law-based contracts:  “Code is Law”  Possible applications of Smart contracts are:  

• Escrow
• Multi-sig transactions
• Deposit
• Micropayment Channels
• Oracles services
• Decentralized applications

Enterprise-class Blockchain platforms 

Target businesses that wish to leverage blockchain technology, but in a more controlled way. Some building blocks of the Blockchain architecture can be modified to feet business needs.   

Off-chain Blockchain Platforms 

Public/Permissionless Blockchains suffer from limitations related to:  

• High latency transactions
• Lack of Privacy/Anonymity
• Limited Scalability

Therefore, some platforms provide the possibility to do off-chain transactions on a Private Blockchain that are connected via a two-way peg to a main Public Blockchain (example Bitcoin). This approach helps leverage the best of the two worlds.