techcamp.hamburg | DIY Blockchain

1. BLOCKCHAIN
DO-IT-YOURSELF

2. DIY-BLOCKCHAIN
ABOUT ME
▸ Maximilian Reichel
▸ Silpion IT-Solutions GmbH
▸ Developer
▸ Architect
▸ Blockchain Enthusiast

3. DIY-BLOCKCHAIN
https://github.com/phramz/diy-blockchain
https://diy.hhx2.com

4. DIY-BLOCKCHAIN
CREDITS
https://libp2p.iohttps://ipfs.io
https://github.com/brix/crypto-js
https://github.com/indutny/elliptic
https://github.com/bitcoinjs/bitcoinjs-lib
bitcoinjs
elliptic
cryptojs
https://bitcoin.org

5. DIY-BLOCKCHAIN
INGREDIENTS
▸ Elliptic Curve (secp256k1)
▸ Hash Function (sha256)
▸ Peer To Peer Networking (ipfs-pubsub)
▸ JavaScript

6. DIY-BLOCKCHAIN
GOALS
▸ Send Transactions (plain message)
▸ Mining Blocks (proof of work)
▸ Consensus (fork resolution)

7. DIY-BLOCKCHAIN
TRANSACTIONS
Tx #1
Tx #3
Tx #2

8. DIY-BLOCKCHAIN
TRANSACTION TEMPLATE
{
"id": "<UUIDv1>",
"type": "message",
"fromAddress": "<???>",
"toAddress": "<???>",
"payload": "hello world!“,
"sign": "<???>"
}
var myTx = diy.tx.newTransaction()

9. DIY-BLOCKCHAIN
PUB-/PRIVATE KEY ENCRYPTION
Source: https://commons.wikimedia.org/wiki/File:Asymmetric_encryption_(colored).png
Author: https://commons.wikimedia.org/wiki/User:Nicobon
License: Creative Commons Attribution-Share Alike 4.0 International

10. DIY-BLOCKCHAIN
ELLIPTIC CURVE DIGITAL SIGNATURE ALGORITHM (SECP256K1)

11. DIY-BLOCKCHAIN
ACCOUNT
[crypto] using seed from mnemonic
a2c901ef81490628f2207f80873211de1a76b0543a87f826f3b6476c130eec9d ↩
bdf26aa38a44adbbdcdd4e69c1c2e196b37e90048c0badba639f11081c281e3c
[crypto] generating elliptic curve public/private keypair from seed
04b9a631c2cd5381fc23d8549c66932d3b458dd40427ffd0b3ad7c790a19546b ↩
af5207ca1230f1d545413e80155bef374dcce3501c81fd547ef782a444dc02625e
4817933462755784230320953029281068998949565844089082598697395564 ↩
3760589390539
[account] generating base58-address
3jFt46azib5597tzEVzVB9sV1CkcH9xDNu7ePb3L9pLLzaw7C4HACN22tQjPmCBZ ↩
7a16LZNz863UcdsyW8McTaxy3LG8EC
diy.account.fromMnemonic("pretty tortoise evoke cinnamon action ↩
fatigue liar rifle identify ceiling gate coast")

12. DIY-BLOCKCHAIN
SIGNED TX (ECDSA)
{
"id": "82c8dfd0-35b7-11e8-9a33-2dc23d28ec78",
"type": "message",
"fromAddress": "3jFt46azib5597tzEVzVB9sV1CkcH9xDNu7e ↩
Pb3L9pLLzaw7C4HACN22tQjPmCBZ7a16LZNz863UcdsyW8McTa ↩
xy3LG8EC",
"toAddress": "3jFt46azib5597tzEVzVB9sV1CkcH9xDNu7e ↩
Pb3L9pLLzaw7C4HACN22tQjPmCBZ7a16LZNz863UcdsyW8McTa ↩
xy3LG8EC",
"payload": "hello world!",
"sign": "24GJCVPehLu5xP6ftmLHXakuz5jo7c4CGnxJ ↩
2YT5gdKStPZ7mrTYD6ERysVf3SH1bUMx9Rse2KG5JmzFVFRjpq ↩
F1Q8a985YqrFpHVLY"
}
myTx = diy.tx.sign(myTX, diy.account.keyPair)

13. DIY-BLOCKCHAIN
BLOCK TEMPLATE
Sign Type FromAddr ToAddr Payload
<SIGN> Message Account A Account B Hello!
<SIGN> Message Account B Account C Hola!
<SIGN> Message Account A Account C Hallo!
<SIGN> Message Account C Account A Salut!
Nonce
Previous
123456
001f2844e83a15b0f1c4507499cc0d7e487c
TransactionsHeader
Hash cc0d7e487c44bb1f28e83a15b0f1c4507499

14. DIY-BLOCKCHAIN
BLOCKCHAIN
Sign Type FromAddr ToAddr Payload
… … … … …
… … … … …
… … … … …
… … … … …
Hash
Previous
<HASH>
<HASH>
Sign Type FromAddr ToAddr Payload
… … … … …
… … … … …
… … … … …
Hash
Previous
<HASH>
<HASH>
Sign Type FromAddr ToAddr Payload
… … … … …
… … … … …
Hash
Previous
<HASH>
<HASH>
#0 (genesis) #1 #2 #…
Height

15. DIY-BLOCKCHAIN
BLOCK
{
"hash": "<SHA256>",
"previous": "<SHA256>",
"generator": "3jFt46azib559…",
"time": 1522597825,
"nonce": 12345,
"height": 10,
"target": 13,
"tx": [<TX>, <TX>, <TX>, …]
}
var myBlock = diy.block.newBlock()

16. DIY-BLOCKCHAIN
PROOF OF WORK (HASHCASH)
Block Hash SHA256(BLOCK)
Target Difficulty 16 (0000xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx)
#1 (nonce=100) SHA256(BLOCK) = 87c44bb1f28e83a15b0f1c4507499cc0d7e4
#2 (nonce=101) SHA256(BLOCK) = 3a15b0f1c4507499cc0d7e487c44bb1f28e8
#3 (nonce=102) SHA256(BLOCK) = 00c0d7e487c44bb1f28e83a15b0f1c450749
#4 (nonce=103) SHA256(BLOCK) = 0000b1f28e83d7e487c4f1c4507494ba15b0
1997 by Adam Back
Sign Type FromAddr ToAddr Payload
<SIGN> Message Account A Account B Hello!
<SIGN> Message Account B Account C Hola!
<SIGN> Message Account A Account C Hallo!
<SIGN> Message Account C Account A Salut!
Nonce
Previous
<RAND>
001f2844e83a15b0f1c4507499cc0d7e487c
TransactionsHeader
Hash ?????

17. DIY-BLOCKCHAIN
MINING

18. DIY-BLOCKCHAIN
CONSENSUS (FORK RESOLUTION)
B2
DIFF 10
B3
DIFF 10
B4
DIFF 11
C4
DIFF 11
C5
DIFF 12
A0
DIFF 10
A1
DIFF 10
A2
DIFF 11
A3
DIFF 11
A4
DIFF 10
A5
DIFF 10
10 + 10 + 11 + 11 + 10 + 10
= 62
10 + 10 + 10 + 10 + 11
= 51
10 + 10 + 10 + 10 + 11 + 12
= 63
A0
DIFF 10
A1
DIFF 10
B2
DIFF 10
B3
DIFF 10
C4
DIFF 11
C5
DIFF 12

19. DIY-BLOCKCHAIN
▸ Verify TXs
▸ Target difficulty
▸ Block height
▸ Block time
▸ …
CONSENSUS