Permissionless

Permissionless

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 to include a proof of work. To prolong the blockchain, bitcoin uses Hashcash puzzles. While Hashcash was designed in 1997 by Adam Back, the original idea was first proposed by Cynthia Dwork and Moni Naor and Eli Ponyatovski in their 1992 paper "Pricing via Processing or Combatting Junk Mail".

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 April 2018, bitcoin has the highest market capitalization.

 

• 1History
• 2Structure
  • 2.1Blocks - Block Time - Hard Forks
  • 2.2Decentralization
  • 2.3Openness - Permissionless -  Permissioned (private) blockchain - Disadvantanges of Private Blockchain -BlockChain Analysis
• 3Uses
  • 3.1Cryptocurrencies
  • 3.2Smart contracts
  • 3.3Financial services
  • 3.4Video games
  • 3.5Energy trading
  • 3.6Supply chain
  • 3.7Domain Names
  • 3.8Other uses
• 4Types
  • 4.1Public blockchains
  • 4.2Private blockchains
  • 4.3Hybrid blockchains
  • 4.4Sidechains
• 5Academic research
  • 5.1Adoption decision
  • 5.2Collaboration
  • 5.3Blockchain and internal audit
  • 5.4Energy use of proof-of-work blockchains
  • 5.5Journals