Bitcoin Q&A: What is a Private Key?

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/bitcoi...
https://github.com/bitcoinbook/bitcoi...
Key to address code: https://github.com/bitcoinbook/bitcoi...

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:   / aantonop  

RELATED:
Bitcoin: Where the Laws of Mathematics Prevail -    • Bitcoin: Where the Laws of Mathematic...  
Advanced Bitcoin Scripting Part 1: Transactions & Multisig -    • Advanced Bitcoin Scripting -- Part 1:...  
Advanced Bitcoin Scripting Part 2: SegWit, Consensus, and Trustware -    • Advanced Bitcoin Scripting -- Part 2:...  
Cryptographic primitives -    • Bitcoin Q&A: Cryptographic Primitives  
Nonces, mining, and quantum computing -    • Bitcoin Q&A: Nonces, Mining, and Quan...  
Public keys vs. addresses -    • Bitcoin Q&A: Public Keys vs. Addresses  
Re-using addresses -    • Bitcoin Q&A: Re-using Addresses  
What happens to our bitcoins during a hard fork? -    • Bitcoin Q&A: What Happens to our Bitc...  
How do mnemonic seeds work? -    • Bitcoin Q&A: How Do Mnemonic Seeds Work?  
Multi-signature and distributed storage -    • Bitcoin Q&A: Multi-signature and Dist...  
What is Segregated Witness? -    • Bitcoin Q&A: What is Segregated Witness?  
SegWit and fork research -    • Bitcoin Q&A: SegWit and Fork Research  
Forkology: A Study of Forks for Newbies -    • Forkology: A Study of Forks for Newbies  
MimbleWimble and Schnorr signatures -    • Bitcoin Q&A: MimbleWimble and Schnorr...  
Protocol development security -    • Bitcoin Q&A: Protocol Development Sec...  
Migrating to post-quantum cryptography -    • Bitcoin Q&A: Migrating to Post-Quantu...  

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   / 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-Mon...

[NEW] THE INTERNET OF MONEY, v2: https://www.amazon.com/Internet-Money...

MASTERING BITCOIN: https://www.amazon.co.uk/Mastering-Bi...

[NEW] MASTERING BITCOIN, 2nd Edition: https://www.amazon.com/Mastering-Bitc...

Translations of MASTERING BITCOIN: https://bitcoinbook.info/translations...

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

Music: "Unbounded" by Orfan (  / orfan  )
Outro Graphics: Phneep (http://www.phneep.com/)
Outro Art: Rock Barcellos (http://www.rockincomics.com.br/)
Join the aantonop Channel: https://aantonop.io/joinaantonopyt