"Introduction technique au Bitcoin" par Gilles Barbier
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This document provides an introduction to Bitcoin and blockchain technology. It explains how Bitcoin transactions work using cryptographic hashes and public/private key pairs. It describes how the blockchain records and verifies transactions in a decentralized manner through a consensus of miners. It discusses how altering the blockchain is difficult and how blocks are added to the blockchain approximately every 10 minutes through a random selection process. It also briefly touches on mining, blockchain forks, the theoretical 21 million bitcoin limit, and alternatives to Bitcoin like altcoins.
"Introduction technique au Bitcoin" par Gilles Barbier
- 1. Introduction technique au Bitcoin Gilles Barbier, TheFamily
- 7. reuse modify emulate no_money Bitcoin Transaction From: To : Amount : 2.5 ea43e18442cc4e511cd2c8c58c25ef5c1 81a5d7dfb65c8e2873eb6f4ec73aaae hashing message with Alice private key Alice Oussama
- 9. > record transactions > manage balance account >guarantee ‘honesty’
- 10. Blockchain :)
- 11. What is the blockchain? time
- 12. How to alter the blockchain? • A fraudulent miner CAN NOT create or modify a valid transaction from someone else • A fraudulent miner COULD • remove any transaction • modify its own transactions • include an invalid transaction (eg. double spend) time
- 13. Decentralised consensus • Complementary from Satoshi Nakamoto (2008): • Emergent consensus: blockchain can be used whenever you want, but consensus is guaranteed after a while (1h)
- 14. Decentralised consensus • independent verification of all new transactions by all miner • independent aggregation of those transactions into a new “block”. • “random” selection of one of these new blocks (one miner wins a “lottery”) • independent verification of this new block by all other miners • independent aggregation of this new block to the blockchain • independent selection of the “official” blockchain as the longest if any fork occurred • Complementary from Satoshi Nakamoto (2008): • Emergent consensus: blockchain can be used whenever you want, but consensus is guaranteed after a while (1h)
- 15. Convergent concensus candidat blocks every 10 min a candidat block is chosen “at random” and added to blockchain after validation by others miners current blockchain
- 16. It’s a bit more complicated than that :) Mining Find a hash of * new transactions * previous block id * random number <= 0000000??????? (“difficulty”)
- 17. Blockchain Convergence two concurrent winners => a blockchain fork blockchain converge blockchain theoretical attack
- 19. reuse modify emulate no_money Bitcoin Transaction From: To : Amount : 2.5 ea43e18442cc4e511cd2c8c58c25ef5c1 81a5d7dfb65c8e2873eb6f4ec73aaae hashing message with Alice private key Alice Oussama
- 21. • Miner reward at t=0: 50 bitcoins • Time to generate a block: 10 min • Halving rate: 4 years • 50 +50 +…+ 25 + 25 + … 12.5 + 12 + …etc • = 50*(1+1/2+1/4+1/8+…)*(4*365*24*6) = 21m !
- 22. Farm
- 28. Pool
- 31. Altcoins
- 32. Blockchain