What is a private key? How are they generated and formatted? Are private keys transmitted when you make a transaction? What are the chances of collision? Will quantum computing making it easy to guess private keys? Does implementing quantum-proof algorithms require an overhaul of the code?

Learn more from the following chapters of ‘Mastering Bitcoin’:
Key to address code: https://github.com/bitcoinbook/bitcoinbook/blob/35f1c62f192dd0eaf1b1c462f88a46e0f5942e16/code/key-to-address-ecc-example.py

These questions are from the MOOC 9.3 and 9.4 sessions, as well as the (rescheduled) April Patreon Q&A session, which took place on March 2nd, March 9th, and May 5th 2018 respectively. Andreas is a teaching fellow with the University of Nicosia. The first course in their Master of Science in Digital Currency degree, DFIN-511: Introduction to Digital Currencies, is offered for free as an open enrollment MOOC course to anyone interested in learning about the fundamental principles. If you want early-access to talks and a chance to participate in the monthly live Q&As with Andreas, become a patron: https://www.patreon.com/aantonop

Bitcoin: Where the Laws of Mathematics Prevail – https://youtu.be/HaJ1hvon0E0
Advanced Bitcoin Scripting Part 1: Transactions & Multisig – https://youtu.be/8FeAXjkmDcQ
Advanced Bitcoin Scripting Part 2: SegWit, Consensus, and Trustware – https://youtu.be/pQbeBduVQ4I
Cryptographic primitives – https://youtu.be/RIckQ6RBt5E
Nonces, mining, and quantum computing – https://youtu.be/d4xXJh677J0
Public keys vs. addresses – https://youtu.be/8es3qQWkEiU
Re-using addresses – https://youtu.be/4A3urPFkx8g
What happens to our bitcoins during a hard fork? – https://youtu.be/sNR76fWd7-0
How do mnemonic seeds work? – https://youtu.be/wWCIQFNf_8g
Multi-signature and distributed storage – https://youtu.be/cAP2u6w_1-k
What is Segregated Witness? – https://youtu.be/dtOjjB4mD8k
SegWit and fork research – https://youtu.be/OorLoi01KEE
Forkology: A Study of Forks for Newbies – https://youtu.be/rpeceXY1QBM
MimbleWimble and Schnorr signatures – https://youtu.be/qloq75ekxv0
Protocol development security – https://youtu.be/4fsL5XWsTJ4
Migrating to post-quantum cryptography – https://youtu.be/dkXKpMku5QY

Andreas M. Antonopoulos is a technologist and serial entrepreneur who has become one of the most well-known and respected figures in bitcoin.

Follow on Twitter: @aantonop https://twitter.com/aantonop
Website: https://antonopoulos.com/

He is the author of two books: “Mastering Bitcoin,” published by O’Reilly Media and considered the best technical guide to bitcoin; “The Internet of Money,” a book about why bitcoin matters.

THE INTERNET OF MONEY, v1: https://www.amazon.co.uk/Internet-Money-collection-Andreas-Antonopoulos/dp/1537000454/ref=asap_bc?ie=UTF8

[NEW] THE INTERNET OF MONEY, v2: https://www.amazon.com/Internet-Money-Andreas-M-Antonopoulos/dp/194791006X/ref=asap_bc?ie=UTF8

MASTERING BITCOIN: https://www.amazon.co.uk/Mastering-Bitcoin-Unlocking-Digital-Cryptocurrencies/dp/1449374042

[NEW] MASTERING BITCOIN, 2nd Edition: https://www.amazon.com/Mastering-Bitcoin-Programming-Open-Blockchain/dp/1491954388

Translations of MASTERING BITCOIN: https://bitcoinbook.info/translations-of-mastering-bitcoin/

Subscribe to the channel to learn more about Bitcoin & open blockchains!

Music: “Unbounded” by Orfan (https://www.facebook.com/Orfan/)
Outro Graphics: Phneep (http://www.phneep.com/)
Outro Art: Rock Barcellos (http://www.rockincomics.com.br/)



  1. But, if the Public address is fundamentally used to receive bitcoins. And if the Private
    key allows you to spend or transfer bitcoins stored at that address. Wouldn't
    the Private key also become public knowledge and subject towards being hacked

  2. The bit where Andreas talks about guessing private key probabilities… mind melt. This guy’s wit is dry and razor sharp, love it, the guy is epic.

  3. Mr. aantonop , I got my Mastering Bitcoin book around 6 months ago, I absolutely devoured it and had to leave a review! Jam-packed with clear information from the beginning to the end. Great work!

  4. If the Public address is fundamentaly used to receive bitcoins. And if the Private key allows you to spend or transfer bitcoins stored at that address. Wouldn't the Private key also become public knowledge and subject towards being hacked ?…

  5. There are 10^77 possible combinations of private keys…there are also around 10^77 atoms in the observable universe. 1 private key per atom. That's how big

  6. All of the videos you put out are gold Andreas! Having you help beginners over and over again is so valuable to the crypto community. Your explanations really get the point across in a friendly way

  7. A few corrections: 10^77 is 10 with 76 zeroes after it, not 77. 10^77 / 10^9 is 10^68 not 10^65. Divide by another billion and it is 10^59, not 10^54, another billion is 10^50, not 10^43.

    Thanks for the great video as always

  8. Hi Andreas, Most of the times blockchain is referenced with respect to financial traction. Could you please help highlight its use case wrt to other applications like immutable database of say… land records or healthcare data ?

  9. So many level 0 questions, ie quantum computers breaking private code, clearly humans need to read more before getting on the forum and typing away to glory. There should be some method of filtering questions like that do in stack overflow

  10. Best Line: In fact at this rate the amount of time it would take you to run through all private keys combinations exceeds the total time of the universe's existence, which depending on whether you apply science or not is either thirteen point four billion years or six thousand years!


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