Download - BdxCoin - Blockchain 101 - 09-04-2014
![Page 1: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/1.jpg)
Bienvenue ! @BdxCoin
![Page 2: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/2.jpg)
Blockchain 101Some tech flavors
![Page 3: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/3.jpg)
● Yay, crypto !
● Bitcoins don’t exist
● The blockchain is Mining
Summary
![Page 4: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/4.jpg)
because in cryptocurrency, there’s crypto
Yay, crypto !
![Page 5: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/5.jpg)
What is a hash ?
data1
data2
data1
5b41362bc82b7f3d56e...
5b41362bc82b7f3d56e...
d98cf53e0c8b77c14a9...SHA-256
![Page 6: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/6.jpg)
What is a Bitcoin address ?
Private key Public key
Wallet
Allows to spend Bitcoins :
Keep it secret !
Used to receive Bitcoins :
You can share it !
![Page 7: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/7.jpg)
“My whole life is a lie” - everyone in this room
Bitcoins don’t exist
![Page 8: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/8.jpg)
● There is no “bitcoin balance” stored
● Balances are computed from transaction history
Bitcoins are transactions
![Page 9: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/9.jpg)
Transaction : simplified
transaction
input output
fee
5 BTC 4.99 BTC
0.01 BTC
![Page 10: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/10.jpg)
Transaction : less simplified
transaction ID
inputs output
fee
4 BTC 4.5 BTC
0.01 BTC
1 BTC
change0.49 BTC
![Page 11: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/11.jpg)
Transactions are grouped in blocks
transaction
transaction
transaction
transaction
Block
reward transaction
![Page 12: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/12.jpg)
Blocks are chained in...
block
block
block
block
Blockchain !
![Page 13: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/13.jpg)
time to turn off your heating system
Blockchain is mining
![Page 14: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/14.jpg)
● Need to make sure blocks are not altered
● -> Let’s hash them !
Avoiding double spending
![Page 15: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/15.jpg)
● Hash the block to make sure it wasn’t altered
● Include hash of the previous block to make sure all the previous blocks weren’t altered !
Block hashing
![Page 16: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/16.jpg)
Block hashing
block
hash
block
hash
![Page 17: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/17.jpg)
A simple hash is very fast to make : one can fork the blockchain
Problem :
![Page 18: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/18.jpg)
● Let’s add some difficulty
● The block hash must meet certain requirements
● Difficulty regulates block generation speed
Proof of Work
![Page 19: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/19.jpg)
● Miners try to find a valid block hash
● The first to find it broadcasts it, and gets the reward + the fees
● Without miners, no blockchain
Mining
![Page 20: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/20.jpg)
● bitcoin.pdf
● en.bitcoin.it/wiki/Category:Technical
● live blockchain monitor : blockchain.info
More tech details ?
![Page 21: BdxCoin - Blockchain 101 - 09-04-2014](https://reader034.vdocument.in/reader034/viewer/2022042814/54c956154a7959de738b45eb/html5/thumbnails/21.jpg)
Thank you !