Bitcoin Q&A: What is a Private Key?
Channel: aantonop
Date: 2018-07-12

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':
https://github.com/bitcoinbook/bitcoinbook/blob/f8b883dcd4e3d1b9adf40fed59b7e898fbd9241f/ch04.asciidoc
https://github.com/bitcoinbook/bitcoinbook/blob/f8b883dcd4e3d1b9adf40fed59b7e898fbd9241f/ch05.asciidoc
Key to address code: https://github.com/bitcoinbook/bitcoinbook/blob/35f1c62f192dd0eaf1b1c462f88a46e0f5942e16/code/key-to-address-ecc-example.py

Chapters
0:00 How is the private key calculated using the elliptic curve mathematical computation? If transactions are public, why can't someone launch a brute-force attack and guess the private key, knowing the fact that we have quantum computers now?
5:15 Do all private keys start with the number 5?
5:52 How do you ensure the private key is transmitted securely and privately into the blockchain?
6:42 Please explain key collision. Also, please give an example of encryption collision. Is it possible to generate a private key that is already being used?
10:30 If transactions are public, why can't someone launch a brute-force attack and guess the private key, knowing the fact that we have quantum computers available now?
12:39 Quantum attacks on Bitcoin and how to protect against them.

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

RELATED:
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/

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