Bitcoin Q&A: Empty blocks, orphan blocks, and valid chains

What is the difference between public keys and addresses? How are new addresses generated? How are change addresses generated? Why have two outputs? Do you still pay fees if you are sending bitcoin to new addresses in your own wallet? What is the VanityGen command? What does the SIG_HASH flag do?

These questions are from the MOOC 9.3 and 9.5 sessions which took place on March 2nd and March 16th, 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.

Are Lightning Network transactions still bitcoin transactions? Do you have to be online? What happens when a party does not commit to an action / send a reimbursement in LN? How will the Lightning Network handle DDoS attacks? How does node banning work?

These questions are from the MOOC 9.5 session which took place on March 16th, 2018. 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.

How many miners and/or pools are there? Can the distribution of miners be determined? Would mining pools be incentivised to merge? Is miner collusion through 51% attacks a present threat? Could they double-spend their coins? How are they impacted by replace-by-fee (RBF)?

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.

Bitcoin Q&A: Mixing services

How do mixing services work? What are CoinJoin transactions? How much could they improve privacy or anonymity in Bitcoin?

Can a blockchain exist without miners, proof-of-work, or blocks? What are the implications for security, trustlessness, and decentralisation? Not all distributed ledgers are blockchains. What is the influence of alternative energy generation on mining in proof-of-work cryptocurrencies? Should we use alternative algorithms that generate "useful work" in addition to mining cryptocurrencies? The hard promises that Bitcoin provides are valuable and useful in themselves. What is the difference between proof-of-work and proof-of-stake?

Note: These sessions were recorded live using Google Hangouts. The audio and video may be slightly out of sync at some points.

These questions are from the MOOC sessions 7.2 and 8.2, covering the Byzantine Generals' Problem, which took place on February 26th 2017 and September 15th 2017 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.

Bitcoin Q&A: Honest nodes and consensus

Bitcoin Q&A: How do mnemonic seeds work?

Bitcoin Q&A: Using paper wallets

How will Bitcoin's infrastructure scale to an everyday currency? When will a business model of small retail transactions make economic sense for cryptocurrencies? What stage of grief are the banks at now?

In this interview, Andreas answers questions about Bitcoin's development into a secure, border-less system that is already influencing geopolitical relations and decision-making, and why the banks' attempt to offer "blockchains in a bottle" is mostly a re-run of the boring and isolated intranets failing to compete against the innovation of the open internet.