Bitcoin Magazine's Technical editor Aaron van Wirdum teams up with Bitcoin core contributor Sjors Provoost to explain Bitcoin one episode at a time.
Lightning Network Channel Payments with Rene Pickhardt - Episode 47
In this episode of Bitcoin Explained, (formerly known as The Van Wirdum Sjorsnado) host Sjors Provoost is joined by Rene Pickhardt to discuss Rene’s paper “Optimally Reliable & Cheap Payment Flows on the Lightning Network”. Rene has spent the last two years researching the reliability of the lightning network, and the reliability of the payment process. They discuss the design principles of the lightning network, the difficulties with routing payments on lightning, probing channel balances, and much more.
Rene's Paper: https://arxiv.org/abs/2107.05322
A First Look at the Chivo App - Episode 46
In this episode of Bitcoin, Explained (formerly known as The Van Wirdum Sjorsnado) hosts Aaron van Wirdum and Sjors Provoost discuss the Chivo application, the Bitcoin wallet, and payment terminal provided by the government of El Salvador. This episode is a little bit different from other episodes of Bitcoin, Explained, because the Chivo app is closed source software. Instead of analyzing the source code and design of the application, Aaron and Sjors have to rely on Aaron’s personal experience with the wallet and payment terminal or what he remembers of that personal experience. The episode opens with some general information about the Chivo Wallet, like why it was developed and who developed it (insofar anything is known about that). Aaron and Sjors go on to discuss Aaron’s experiences with the wallet and speculate what that means for the design. After that, they discuss the design of the payment terminal that’s included in the application, and also briefly touch on the Chivo ATMs that have been deployed across the country. Finally, Aaron and Sjors discuss the difference in philosophy between the design of the Chivo application and Bitcoin’s free and open-source software culture.
Bitcoin Core 22.0 Explained - Episode 45
The Van Wirdum Sjorsnado has rebranded, and is now called Bitcoin, Explained!
In this episode of Bitcoin, Explained, hosts Aaron van Wirdum and Sjors Provoost discuss Bitcoin Core 22.0, the latest major release of the Bitcoin Core software client, currently the de facto reference implementation of the Bitcoin protocol. Aaron and Sjors highlight several improvements to the Bitcoin Core software.
The first of these is hardware wallet support in the graphical user interface (GUI). While hardware wallet support has been rolling out across several previous Bitcoin Core releases, it is now fully available in the GUI. The second highlighted upgrade is support for the Invisible Internet Project (I2P), a Tor-like internet privacy layer. Aaron and Sjors also briefly touch on the differences between I2P and Tor.
The third upgrade discussed in the episode is Taproot support. While Taproot activation logic was already included in Bitcoin Core 0.21.1 Bitcoin Core 22.0 is the first major Bitcoin Core release ready to support Taproot when it activates this November, and includes some basic Taproot functionality.
The fourth upgrade that Aaron and Sjors discuss is an update to the testmempoolaccept logic, which paves the way to a bigger package relay upgrade. This could in a future release allow transactions to be transmitted over the Bitcoin network in packages including several transactions at the same time.
Additionally, Aaron and Sjors briefly discuss an extension to create multisig and add multisig address, the new NAT-PMP option, and more.
Basis of Lightning Technology 12
Sjors is back!
In this episode of The Van Wirdum Sjorsnado, hosts Aaron van Wirdum and Sjors Provoost discuss BOLT 12 (Basis of Lightning Technology 12), a newly proposed Lightning Network specification for “offers”, a type of “meta invoices” designed by c-lightning developer Rusty Russell.
Where coins on Bitcoin’s base layer are sent to addresses, the Lightning network uses invoices. Invoices communicate the requested amount, node destination, and the hash of a secret which is used for payment routing. This works, but has a number of limitations, Sjors explains, notably that the amount must be bitcoin-denominated (as opposed for fiat denominated), and the invoice can only be used once.
BOLT 12, which has been implemented in c-ligtning, is a way to essentially refer a payer to the node that is to be paid, in order to request a new invoice. While the BOLT 12 offer can be static and reusable — it always refers to the same node — the payee can generate new invoices on the fly when requested, allowing for much more flexibility, Sjors explains.
Finally, Aaron and Sjors discuss how the new BOLT 12 messages are communicated over the Lightning Network through an update to the BOLT 7 specification for message relay.
Hardware Wallets and Blockstream’s Jade wallet
In this episode of The Van Wirdum Sjorsnado, Aaron van Wirdum hosts one more interview without his regular cohost Sjors Provoost. Instead, he is joined by Blockstream’s Lawrence Nahum, one of the developers behind the Jade wallet, and Ben Kaufman, one of the developers of the Spectre wallet, which is specifically designed to work with hardware wallets.
Aaron, Lawrence and Ben talk about what hardware wallets are, and discuss the design tradeoffs that different hardware wallets have taken by focussing on the Trezor, Ledger and ColdCard specifically. In this light, Lawrence and Ben explain what secure elements and secure chips are, and why some hardware wallets choose to rely on using such chips more than others.
Then, Lawrence explains which tradeoffs the Jade wallet makes. He also details how an additional server-based security step is used to further secure the Jade wallet, and briefly outlines some additional differences in hardware wallet designs, for example those focused on usability.
Finally, Aaron, Lawrence and Ben discuss whether the concept of hardware wallets are a good idea in the first place, or if it would perhaps be better to use dedicated smartphones to store your bitcoin.
And don’t worry, Sjors will be back for episode 44!
The Bitcoin Beach Wallet (Bitcoin Beach Special)
A Bitcoin Beach special! In this episode of The Van Wirdum Sjorsnado host Aaron van Wirdum speaks with Bitcoin Beach Wallet developer Nicolas Burtey — without cohost Sjors Provoost this time. Aaron and Nicolas met up in El Zonte, El Salvador — which has been dubbed Bitcoin Beach — to discuss the Bitcoin Beach Wallet, a Bitcoin and Lightning wallet specifically designed for use in the small Central American coastal town frequented by surfers and, now, bitcoiners.
Aaron and Nicolas discuss the pros and cons of custodial and non-custodial Lightning wallets, and Nicolas explains why he opted to make the Bitcoin Beach Wallet a shared-custodial wallet, and what that means exactly.
They go one to discuss some of the design decisions and tradeoffs that the Bitcoin Beach Wallet has made, which include ledger-based payments between Bitcoin Beach Wallet users as well as the webpage-based zero invoice payments to facilitate payments from other Lightning wallets. while Nicolas speculates about a potential cross-wallet user account system to further improve the Lightning user experience over time.
Aaron and Nicolas also discuss some of the subtle incompatibilities between different Lightning wallets that use different techniques for routing payments, privacy considerations versus user experience in a community like El Zonte’s, and more.
Great technical explanations
Great new technical podcast!
This Bitcoin Magazine podcast now has its own podcast feed! So happy to just get my weekly bitcoin fix from Aaron and Sjors!