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Cryptocurrency, a deep dive

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Cryptocurrency, a deep dive

  1. 1. CRYPTOCURRENCIES A DEEP DIVE OWASP KHARTOUM
  2. 2. BIO - Khaled Farah. - Volunteer at Owasp Khartoum . - GM, Co-Founder at SEMICOLON ICT. semicolon-ict.com twitter : @_khaledfarah
  3. 3. #BITCOIN #BLOCKCHAIN #ETHEREUM #DECENTRILAZED #PUBLIC_KEY #PRIVATE_KEY #WALLET #POW #UNSPENT_TRANSACTION #MINING #ICO Keywords
  4. 4. FUN PART ‫تمهيد‬
  5. 5. Money Value • Controlled issuing. • Adoption. • Utility. What gives bank notes value ? • The price of the USD is calculated purely on supply and demand. • Dollars - or SDGs - in your pocket may lose all value one day.
  6. 6. Cryptocurrencies != Bitcoin 1380+ coins as of January 2018
  7. 7. BITCOIN - History • Founded in 2009 • Unknown founder “Satoshi Nakamoto” • Guy named Koch bought 5,000 bitcoins in 2009 for $27. • Another guy paid 10,000 bitcoins for a pizza. • Today, one Bitcoin is equal to 7500-8000$. • Many alt-coins followed bitcoin.
  8. 8. What makes bitcoin special • It’s not Bitcoin, It’s what’s behind it. • Blockchain • What makes bitcoin special. • Limited “21 Million”. • Decentralised • Secure • Availability • Integrity • Confidentiality • Low transaction fees. * • Instant. *
  9. 9. Bitcoin in Sudan • We have a bitcoin community in Sudan.https://web.facebook.com/groups/ 794021010648172/ • Softwex accepts bitcoin as a payment method. https:// www.softwex.com
  10. 10. SCIENCE PART
  11. 11. How does bitcoin work? • What is bitcoin ? • How is stored? • Why is it secure? • Where is it stored ? • What is a wallet ?
  12. 12. How does bitcoin work?
  13. 13. PKI encryption
  14. 14. PKI encryption Confidentiality
  15. 15. PKI encryption Integrity
  16. 16. Private key generation The size of bitcoin's private key space,(2^256^) is an unfathomably large number. It is approximately 10^77^ in decimal. For comparison, the visible universe is estimated to contain 10^80^ atoms.
  17. 17. Public Key Cryptography and Cryptocurrency It’s not about encryption, it’s about signing. “integrity” Elliptic curve multiplication
  18. 18. Blockchain In simple words • A ledger. • Write and read only “No edit”. • Series of blocks. • Each block contains a list of verified transactions. • Miners compete to add the next block to the blockchain. • Only one wins
  19. 19. Blockchain In simple words • “People” encrypting data and sending it to the pool “Private key”. • “People” taking this data and verifying it “public key” • “People” claiming ownership after the data is verified “Private key”.
  20. 20. Storing bitcoins - You don’t store bitcoin. - You claim ownership of an address of unspent transaction.
  21. 21. Bitcoin transaction Transactions has two parts • Input • Address “Unspent transaction” • Output • Receiver address • Your address “remainder” Input - Output = Transaction fees
  22. 22. Bitcoin transaction - A transaction tells the network that the owner of some bitcoin value has authorised the transfer of that value to another owner. - The new owner can now spend the bitcoin by creating another transaction that authorises transfer to another owner, and so on, in a chain of ownership.
  23. 23. Mining • Transaction verifiers. • Compete for the chance of adding the next “Block” in the blockchain. • Rewarded two ways : • Transaction fees. • Mining fees. • Protocols : Proof of work (Bitcoin) , Proof of stake “Ethereum”
  24. 24. Proof of work • Multiple nodes compete. Only one winner ( next block ). • Verify each transaction. • Difficulty is adjustable. • One block every 10 mins. • Mekle root.
  25. 25. Wallet • Different types of wallets • Pairs of keys • Deterministic wallets • Can be a hardware wallet, mobile app or a desktop app. • Keyword here is “Private key” storing
  26. 26. FUN PART AGAIN ‫حقائق‬
  27. 27. Bitcoin price • Difference between price and value? • Price depends on supply and demand => volatile. • Value depends on adoption & utility.
  28. 28. Quick stats - Ethereum – 20 transactions per second - Visa – 1,667 transaction per second - PayPal – 193 transactions per second average - 7 transactions/second. - 1 block per 10 mins. - 1 Megabytes block. - 12 Bitcoins is the miner reward per block. Bitcoin Other currencies
  29. 29. How to scale bitcoin? • Increase block size ? Including more transactions per block. • Minimise transaction size?
  30. 30. New trends • Bitcoin is a store currency. “Gold” • Other currencies are spend currencies
  31. 31. Bitcoin issues “Not cryptocurrencies” • Slow transaction verification “Promised to be solved using lightening networks”. • High transaction fees “miners”. • Untraceable transactions. “Regulations”
  32. 32. Reading topics • Initial coin offering. • Lightning network • Smart contracts
  33. 33. Final remarks • Value depends on adoption & utility. • Blockchain potential is much bigger than bitcoin “Currencies”. • Many applications can be decentralised.
  34. 34. Resources • Bitcoin official website: https://bitcoin.org/en/ • Mastering bitcoin: https://github.com/bitcoinbook/bitcoinbook • Podcast: https://explainblockchain.io/ • Twitter Thread: https://twitter.com/Sudan_Voices (khatab Elbadawi)
  35. 35. THANK YOU

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