Title Text

Digital Currency & Blockchain

Lecture 8


  • User Security & Key management



  • Bitcoin ATM - cash, anonymous, fast and expensive
  • Localbitcoins   - similar but face to face
  • Online Broker - fast, no registration, higher fee
  • Bitcoin Exchange - cheap, big volumes, verified

How to get crypto


  • 12-24 words
  • Recovery and Backup
  • Out of 2048 words (BIP39)
  • Multiple languages (EN, FR, CZ, IT, ES, JAP..)
  • "Brainwallet"
  • Bitcoin Wiki on Seeds
  • Everything about Address Generation
  • Example:
    witch collapse practice feed shame open despair creek road again ice least



  • Base58 is a set of characters you can use to represent big numbers in a shorter and more user-friendly format.
  • The more characters you have in your base, the less of them you will need to use to represent big numbers. So the bigger your base, the shorter your “number” can be.
  • Because 58 is the number of characters you are left with when you use all the characters in the alphanumeric alphabet (62), but remove all the easily mistakable characters like 0, O, l and I.

Types of Wallets

Paper Wallet

HW Wallets - Trezor


-  www.trezor.io

- 1st in the world

- Open source HW aj SW

- Blind keyboard generated randomly

- Passphrase protected

- PIN code

- almost impossible remote attacks

HW Wallets - Trezor Model T


 - Colourful display

- Open source HW aj SW

- Random generated keyboard 

- Passphrase protected

- PIN code

- Password Manager

- Shamir scheme (SSSS)

Ledger Nano S



- Open source SW but no HW

- Harder to use

- Small Memory for a limited amount of apps

- Closer-sourced Secure Chip

SW wallets

Web wallets




BTC & Omni assets:



Contest I.

Whoever sends me ETH address first -- gets a reward


Contest II.


Whoever shows/sends me BTC address QR code gets a reward!


Crypto Steel


Bitcoin ATMs


Bitcoin ATMs


- quite anonymous in some countries

- no ID required usually

- KYC-less purchase up to 5k

- 2way ATMs as well



- www.xmr.to  --> BTC to XMR anonymously


- Shapeshift 

- Binance

- Uniswap




  • easy
  • cheap
  • No tech background required
  • Possible to gamble and trade


  • No Control of private keys
  • If FIAT exchange, verfification required
  • phishing a hackers attacks



Exchanges II.

  • Trading against others
  • Orderbook - supply and demand
  • Low fees
  • Many coins, higher liquidity
  • Registration, Verificaiton AML, KYC
  • Margin, Funding, Futures, CFD
  • Bitstamp, Coinmate, Bittrex, Bitfinex, Kraken 


Exchanges III.

  • Sophisticated tools:
    • Limit order, market price, stoploss, trailing stop, hidden
    • Graphs & analytical tools, indicators
    • Market depth, liquidity



UNI - L8 (User Security)

By David Stancel

UNI - L8 (User Security)

User Security + Key management

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