Bitcoin Q&A: Honest Nodes and Consensus
Channel: aantonop
Date: 2018-04-11

How are hashes and transactions determined to be "valid" in Bitcoin? How are nodes determined to be "honest"? How much of this process is automated? Consensus is an agreement on what "valid" is.

Chapters
0:00 What is the expected pattern that a hash is reviewed against to determine a valid block? Are the attempts to find the nonce manually or automatically implemented?
2:53 What do you mean by transaction validation? How does that process work?
6:38 What is the difference between miners and nodes?
8:33 What are the upload and download requirements for an internet connection to be okay with Bitcoin nodes?
9:44 Does the block need to be finished for the validation of all its transactions?
11:06 Why should I run a full node if I am not a miner?
13:39 On what basis does my node connect to other nodes? Can I be cheated and connect to dishonest nodes?
15:43 Could someone create enough virtual lieutenants to bring down the General and replace him with a new one of their choice -- conduct a blockchain coup d'état, as it were?
18:07 How does the network verify that the winning miner solution was correct? How many times is the solution verified, and by how many network participants?
19:57 On my response about cutting connections with a node that is lying, do all nodes find it at the same time? Can there be a mixed understanding of what is an invalid node? How is consensus found?

These questions are from the MOOC sessions 7.2, 8.2, and 9.2 covering the Byzantine Generals' Problem, which took place on February 26th 2017, September 15th 2017, and February 23rd 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:
Consensus Algorithms, Blockchain Technology, and Bitcoin - https://youtu.be/fw3WkySh_Ho
Advanced Bitcoin Scripting Part 1: Transactions and Multisig - https://youtu.be/8FeAXjkmDcQ
Advanced Bitcoin Scripting Part 2: SegWit, Consensus, and Trustware - https://youtu.be/pQbeBduVQ4I
What is Consensus: Rules without Rulers - https://youtu.be/2tqo7PX5Pyc
Forkology: A Study of Forks for Newbies - https://youtu.be/rpeceXY1QBM
Bitcoin: Where the Laws of Mathematics Prevail - https://youtu.be/HaJ1hvon0E0
The rules of Bitcoin (part 1) - https://youtu.be/VnQu4uylfOs
The rules of Bitcoin (part 2) - https://youtu.be/vtIp0GP4w1E
Decentralized power, leaderless governance - https://youtu.be/E5VbDlQTPzU
Scaling, trust, and trade-offs - https://youtu.be/vCxmHwqyJWU
Why running a node is important - https://youtu.be/oX0Yrv-6jVs
Running nodes and payment channels - https://youtu.be/ndcfBfE_yoY
What happens during a fork? - https://youtu.be/XBk8hBJ1xVo
SegWit adoption - https://youtu.be/KCsTVTRk6I4
How do mnemonic seeds work? - https://youtu.be/wWCIQFNf_8g

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

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/)
Join the aantonop Channel: https://aantonop.io/joinaantonopyt