On Todays Episode of Let's Talk Bitcoin... Stephanie Murphy, Andreas Antonopoulos, Jonathan Mohan, and Adam B. Levine sit down for the first of our two-part discussion on the nascent but rapidly improving Lightning Network. Selected Excerpts transcribed courtesy of Professor Meow Lightning Network Privacy Jonathan Mohan: What level of obfuscation does lightning provide and does it intend to get more obfuscation? Andreas Antonopoulos: The routing network today provides a very significant level of privacy. Keep in mind that the only people who see a transaction on Lightning (unlike Bitcoin where transactions are published on the ledger), the only people who see a transaction are the nodes through which the transaction flows. People ask how many transactions are happening on Lightning network? The answer is a very comforting: we have no clue; it's impossible to measure. Stephanie Murphy: We just know the total volume of the value of Bitcoin that's being transacted there? Andreas Antonopoulos: No, we know the total volume of channels that have been advertised as capable of routing. We don't know the channels that have not been advertising, and we don't know how much of that capacity is being used. Keep in mind capacity is not velocity. You could have entire secret sub-networks within lightning. Adam B. Levine: Do you think there will be a differentiation between multiple public networks? Or is there one big public network, then lots of people can have private networks? Andreas Antonopoulos: It's one big public network, and within it, lots of people can have what is effectively Virtual Private Networks on top. So it's like VPNs on the Internet - those are invisible. Just like the Internet, what you see, what is advertised, announced, and broadcasted to the world is the tip of the iceberg. There's a very big and deep iceberg underneath that may not be visible. We have no way of measuring or knowing how big that is, and that's how it should be. Neutrino Adam B. Levine: Andreas, have you looked into neutrino much? Andreas Antonopoulos: Yeah, I've actually been running neutrino as well for a while. This is a really amazing development. It's a massive improvement over the old model - the model isn't really the SPV that's described in the Bitcoin whitepaper. Basically what it does is it allows you to send a compressed set that describes the transactions that are in a block, send that to a light client, so that it can request to receive any blocks that have transactions of interest to it. It can download the full block or the full transaction set only for those things that it's interested in, while not telling the nodes that it's connected to what it's interested in. That's a massive increase in privacy. This is not just for Lightning, that's important to understand. Neutrino can be used as a light client for on-chain Bitcoin transactions to massively increase the privacy of mobile wallets. Of course, it can be used so that you can have a Lightning wallet that's not necessarily connected to your own lightning node, but also doesn't break your privacy. Adam B. Levine: The entire Bitcoin blockchain can get summarized down to 40 Megs? Andreas Antonopoulos: Yes, that's for the initial sync. After that, it can continue to get updated summaries that are even smaller (in the kilobyte size) in order to maintain synchronization. So it's doing full validation without having a full copy of the block. Of course, all of this depends on having full nodes that are willing to publish Golomb coded sets to feed to neutrino clients. We still need a lot of people to run full nodes, but the bandwidth burden on those nodes to serve neutrino clients obviously drastically reduced. A single full node can serve a lot of neutrino clients very efficiently. Atomic Multipath Payments Andreas Antonopoulos: This is a routing infrastructure improvement - it will be completely transparent to users. Instead of just constructing a single route that originates from your node