35:03

Ep. 21 Dec 18, 2020

Why Open Source Matters for Bitcoin - NADO 21

In this episode of The Van Wirdum Sjorsnado, Aaron and Sjors discuss why it matters that Bitcoin software is open source… and why even open source software doesn’t necessarily solve all software-specific trust issues. In theory, the fact that most Bitcoin nodes, wallets and applications are open source should ensure that developers can’t include malicious code in the programs: anyone can inspect the source code for malware. In practice, however, the number of people with enough expertise to do this is limited, while the reliance of some Bitcoin projects on external code libraries (“dependencies”) makes it even harder. Furthermore, even if the open source code is sound, this doesn’t guarantee that the binaries (computer code) really correspond with the open source code. Aaron and Sjors explain how this risk is largely mitigated in Bitcoin through a process called Gitian building, where several Bitcoin Core developers sign the binaries if, and only if, they all produced the exact same binaries from the same source code. This requires special compiler software. Finally, Aaron and Sjors discuss Guix, a relatively new project that goes above and beyond the Gitian process, to minimize the level of trust required to turn source code into binaries — including trust in the compiler itself. Chapters 00:00:00 Free software and open source 00:04:46 Why Bitcoin needs reviewable source code 00:09:02 Authenticating downloads with checksums and signatures 00:10:32 Matching binaries to source code 00:14:06 Gitian and reproducible builds 00:16:06 Dependency risks and the Copay attack 00:23:03 Trusting the compiler and build environment 00:24:54 Guix and bootstrapping the toolchain 00:31:00 Hardware trust and Wallet Scrutiny

23:19

Ep. 20 Dec 11, 2020

RSK, federated sidechains and Powpeg - NADO 20

In this episode of The Van Wirdum Sjorsnado, hosts Aaron van Wirdum and Sjors Provoost discuss RSK’s shift from a federated sidechain model to the project’s new Powpeg solution. RSK is a merge mined Ethereum-like Bitcoin sidechain developed by IOVlabs. Bitcoin users can effectively move their coins to this blockchain that operates more like Ethereum, and move the coins back to the Bitcoin blockchain when they so choose. Some Bitcoin miners utilize their hashpower to mine bocks on the sidechain, and earn some extra transaction fees by doing so.The tricky part of any sidechain is allowing users to securely move their coins between blockchains. This is technically done by locking coins on the Bitcoin blockchain and issuing corresponding coins on the sidechain, and vice versa: locking coins on the sidechain to unlock the coins on the Bitcoin blockchain.So far, RSK did this by locking the coins into a multi-signature address, for which the private keys were controlled by a group of well-known companies. A majority of them was needed to unlock the coins, which they were to only do if and when the corresponding sidechain coins were locked.RSK is now switching to a Powpeg model where the keys to the multi-signature address are controlled by special tamper-proof hardware modules that are in turn programmed to only unlock coins on the Bitcoin blockchain if and when the corresponding coins on the sidechain are locked, and the transactions to lock these coins up have a significant number of confirmations.Aaron and Sjors explain how this works exactly, and discuss some of Powpeg’s security tradeoffs. Chapters 00:00:00 Podcast feed announcement 00:01:13 RSK, Ethereum-like functionality and sidechains 00:05:49 How RSK merged mining works 00:08:28 The federated two-way peg 00:12:05 Powpeg hardware and withdrawal confirmations 00:14:04 Hardware trust, backdoors and availability 00:18:18 Drivechains and alternative trust assumptions 00:20:15 Miner incentives and sidechain security tradeoffs

20:39

Ep. 19 Dec 4, 2020

Mempools, Child Pays for Parent, and Package Relay - NADO 19

In this episode of The Van Wirdum Sjorsnado, hosts Aaron van Wirdum and Sjors Provoost discussed Bitcoin mempools, Child Pays For Parent (CPFP) and package relay. Package relay is the project that Gloria Zhao will work on as part of her Brink fellowship, which was announced earlier this week, and would make the Lightning Network more robust (among other benefits). Mempools are the collections of unconfirmed transactions stored by nodes, from which they forward transactions to peers. Miners usually select the transactions from their mempools that include the highest fees, to include these in the blocks they mine. Mempools can get full, however, at which point transactions that pay the lowest fees are ejected. This is actually a problem in context of CPFP, a trick that lets users speed up low-fee transactions by spending the coins from that transactions in a new transaction with a high fee to compensate. Tricks like these can be particularly important in the context of time-sensitive protocols like the Lightning Network. In this episode, van Wirdum and Provoost explained how package relay could enable CPFP, even in cases where low-fee transactions are dropped from mempools, by bundling transactions into packets. And they explore why this may be easier said than done. Chapters 00:00:00 Brink, Gloria Zhao and package relay 00:02:31 What the mempool stores 00:05:20 What happens when mempools fill up? 00:06:11 Child pays for parent and Lightning deadlines 00:11:36 Why CPFP can fail under congestion 00:13:19 Relaying parent and child as a package 00:14:49 Abuse risks, eviction and resource limits 00:17:22 Small implementation steps toward package relay

16:00

Ep. 18 Nov 20, 2020

Erebus Attacks and how to stop them with ASMAP - NADO 18

In this episode of The Van Wirdum Sjorsnado, Aaron and Sjors discuss the Erebus Attack. The episode is a follow-up from last week’s episode on Eclipse Attacks, a type of attack that isolates a Bitcoin node by occupying all of its connection slots to block the node from receiving any transactions. Erebus Attacks are Eclipse Attacks where an attacker essentially spoofs a whole part of the internet. Chapters 00:00:00 The Erebus attack 00:01:15 Eclipse attacks and IP diversity recap 00:03:24 Autonomous systems and internet bottlenecks 00:07:07 How Erebus eclipses a node 00:08:07 Mapping internet routes with RIPE 00:10:21 Compressing bottlenecks with ASMap 00:12:35 Using and auditing ASMap in Bitcoin Core 00:13:36 Stronger peer diversity and remaining limits Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Music: Song Title: Segwit Sounds By: The NakamoTones Album: Citadel Music Produced by: Bitcoin Audio

20:32

Ep. 17 Nov 13, 2020

Bitcoin Eclipse Attacks And How To Stop Them - NADO 17

In this episode of The Van Wirdum Sjorsnado, Aaron and Sjors discuss Eclipse attacks. More specifically, they discuss the 2015 paper “Eclipse Attacks on Bitcoin’s Peer-to-Peer Network,” written by Ethan Heilman, Alison Kendler, Aviv Zohar and Sharon Goldberg, from Boston University and Hebrew University/MSR Israel. Chapters 00:00:00 The eclipse-attack research paper 00:01:57 What is an eclipse attack? 00:03:22 Double spending against an isolated node 00:05:54 Splitting miners to amplify the attack 00:08:08 Poisoning peer addresses and connection buckets 00:11:43 Crashes, restarts and capturing connections 00:13:05 Address-selection defenses and feeler connections 00:15:10 Remembering peers across restarts 00:16:26 More outbound peers and block-only connections 00:18:10 Satellites, hidden nodes and remaining defenses Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Music: Song Title: Segwit Sounds By: The NakamoTones Album: Citadel Music Produced by: Bitcoin Audio

31:12

Ep. 16 Nov 6, 2020

Open Timestamps - NADO 16

In this episode of The Van Wirdum Sjorsnado, Aaron and Sjors discuss Open Timestamps, a Bitcoin-based time stamping project by applied cryptography consultant and former Bitcoin Core contributor Peter Todd. Open Timestamps leverages the security of the Bitcoin blockchain to timestamp any type of data, allowing for irrefutable proof that that data existed at a particular point in time. Chapters 00:00:00 OpenTimestamps and proof of prior existence 00:03:27 Document hashes and SHA256 00:05:54 Merkle trees and compact blockchain commitments 00:08:45 Calendar servers and collecting timestamp proofs 00:14:06 Verifying proofs with a Bitcoin node 00:15:42 Email signatures and timestamped signing keys 00:18:36 What timestamps cannot prove 00:23:18 Git history, the Genesis block and fraud limits 00:27:15 Haber, Stornetta and the roots of Bitcoin timestamping Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Music: Song Title: Segwit Sounds By: The NakamoTones Album: Citadel Music Produced by: Bitcoin Audio

31:46

Ep. 15 Oct 30, 2020

Utreexo w/ Ruben Somsen - NADO 15

On this episode of The Van Wirdum Sjorsnado, Aaron and Sjors are once again joined by Ruben Somsen. This time, the trio doesn’t discuss one of Somsen’s own proposals, but they dive into a concept by Tadge Dryja called Utreexo. Helpful links: https://bitcoinmagazine.com/articles/bitcoins-growing-utxo-problem-and-how-utreexo-can-help-solve-it Chapters 00:00:00 AssumeUTXO and assumevalid: an extra distinction 00:04:29 Utreexo and the growing UTXO memory problem 00:10:24 Pruning the UTXO set and reversing the burden of proof 00:13:04 Merkle forests, proofs and updating roots 00:18:34 Bridge nodes supply transaction and block proofs 00:22:01 Could proofs become part of a soft fork? 00:23:54 Specialized hardware for full-node validation 00:25:34 Tiny snapshots and syncing a phone node 00:27:10 Parallel and backward validation 00:29:13 Accumulator choices and bandwidth tradeoffs Support the Show!Follow Bitcoin Magazine on Twitter @BitcoinMagazineFollow Aaron van Wirdum @AaronvanWFollow Sjors Provoost @provoostFollow Ruben Somsen @SomsenRuben Music:Song Title: Segwit SoundsBy: The NakamoTonesAlbum: Citadel MusicProduced by: Bitcoin Audio

23:21

Ep. 14 Oct 23, 2020

Headers First, Assume Valid and Assume UTXO - NADO 14

On this episode of The Van Wirdum Sjorsnado, Aaron and Sjors discuss “Assume UTXO”, a proposal and project by Chaincode Labs alumni James O’Beirne. One of the biggest bottlenecks for scaling Bitcoin — if not the biggest one — is initial block download: the time it takes for a Bitcoin node to synchronize with the Bitcoin network, as it needs to process all historic transactions and blocks in order to construct the latest UTXO-set: the current state of bitcoin-ownership. Aaron and Sjors explain some of the ways sync-time has been sped up over time. First, sync-time was improved through “Headers First” synchronization, which ensures that new Bitcoin nodes don’t waste time validating (potentially) weaker blockchains. In recent years, sync-time has been improved with “Assume Valid”, an optional shortcut that lets nodes skip signature verification of older transactions, instead trusting that the Bitcoin Core development process in combination with the resource-expensive nature of mining offers a reliable version of transaction history. Finally, they explain how the security assumptions underpinning Assume Valid could be extended to allow for the potential future upgrade Assume UTXO to offer new Bitcoin Core users a speedy solution to get up to speed with the Bitcoin network, sacrificing a minimal amount of security during the initial bootstrapping phase. Helpful Links: Chaincode podcast about the same:[ https://www.youtube.com/watch?v=knBHvzKsIOY](https://www.youtube.com/watch?v=knBHvzKsIOY) Pull request: https://github.com/bitcoin/bitcoin/issues/15605 Chapters 00:00:00 AssumeUTXO and faster Bitcoin synchronization 00:01:42 Headers-first sync and rejecting low-work detours 00:07:23 Assumevalid skips historical signature checks 00:09:57 Trust, source review and disabling assumevalid 00:11:49 AssumeUTXO snapshots and background validation 00:15:29 What if historical validation were skipped? 00:17:05 Loading snapshots and future peer-to-peer delivery 00:19:35 Experimental rollout and security tradeoffs 00:20:20 UTXO commitments and consensus risks Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Music: Song Title: Segwit Sounds By: The NakamoTones Album: Citadel Music Produced by: Bitcoin Audio

18:48

Ep. 13 Oct 16, 2020

Bitcoin Core 0.21 supports Tor v3 - NADO 13

Bitcoin Core 0.21 will support Tor v3 addresses. Aaron and Sjors explain what this means and why it matters, and also discuss how new Bitcoin nodes find existing Bitcoin nodes when they bootstrap to the network. Helpful Links: * Tor V3 (onion) address support in Bitcoin Core: * the ADDRv2 message added in BIP155 that allows nodes to gossip those new Tor addresses: https://github.com/bitcoin/bips/blob/master/bip-0155.mediawiki#Specification * DNS seeds and the bootstrap problem: https://stackoverflow.com/questions/41673073/how-does-the-bitcoin-client-determine-the-first-ip-address-to-connect Chapters 00:00:00 Tor and onion-service basics 00:02:35 Privacy benefits for Bitcoin nodes 00:03:40 Longer Tor v3 addresses 00:04:47 Peer discovery and the old address format 00:07:04 BIP155 and the addrv2 message 00:08:18 Bootstrapping a node and how DNS works 00:11:40 DNS seeds, centralization and public scrutiny 00:13:26 Fallback seeds and remembering known peers 00:16:29 Automatic Tor v3 services and podcast news Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Follow Ruben Somsen @SomsenRuben Music: Song Title: Segwit Sounds By: The NakamoTones Album: Citadel Music Produced by: Bitcoin Audio

40:12

Ep. 12 Oct 9, 2020

The Perpetual One-Way Peg - NADO 12

In this episode of The Van Wirdum Sjorsnado, Ruben Somsen returns to explain his proposal to combine blind merged mining and perpetual one-way pegs in order to create a new type of sidechain. The bad news: it won’t make you rich but it could help scale Bitcoin! Helpful Links: https://medium.com/@RubenSomsen/21-million-bitcoins-to-rule-all-sidechains-the-perpetual-one-way-peg-96cb2f8ac302 Chapters 00:00:00 Ruben returns and the new podcast feed 00:02:44 Blind merged chains and their use cases 00:06:27 How blind merge mining works 00:08:53 Fee bidding, transaction chains and ANYPREVOUT 00:16:52 Censorship, reorgs and security incentives 00:21:28 Covenants inside the transaction scaffold 00:24:38 Burning bitcoin for a perpetual one-way peg 00:29:27 Token price limits and the burned-house objection 00:31:08 Why block space needs value and fees 00:36:04 Separating blockchain technology from speculation Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Follow Ruben Somsen @SomsenRuben Music: Song Title: Segwit Sounds By: The NakamoTones Album: Citadel Music Produced by: Bitcoin Audio

32:49

Ep. 11 Oct 2, 2020

Accounts for Bitcoin, Easypaysy! - NADO 11

In this episode Sjors and Aaron discuss Jose Femenias’ Easypaysy proposal, an account system for Bitcoin, on Bitcoin. They also announce groundbreaking news: The Van Wirdum Sjorsnado now has its own RSS-feed! Aaron’s article covering Easypaysy on Bitcoin Magazine https://bitcoinmagazine.com/articles/bitcoin-need-accounts-one-developer-thinks-figured The BIP in Github https://github.com/bitcoin/bips/blob/master/bip-0047.mediawiki Chapters 00:00:00 The new feed and the problem with address reuse 00:02:40 Creating an Easypaysy account on Bitcoin 00:08:16 Payment types: reused keys and address requests 00:10:32 Stealth-style payments and blockchain scanning 00:13:19 Finding accounts with short identifiers 00:15:26 Privacy pitfalls and the BIP47 comparison 00:19:48 Bootstrapping accounts and recurring payments 00:23:39 Non-repudiation and proof of payment 00:26:19 Protocol simplification and discovery updates 00:28:38 Adoption, Lightning offers and on-chain alternatives Support the Show!Follow Bitcoin Magazine on Twitter @BitcoinMagazineFollow Aaron van Wirdum @AaronvanWFollow Sjors Provoost @provoost Music!Title: Segwit SoundsBy: The NakamoTonesAlbum: Citadel MusicProduced by: Bitcoin Audio

15:25

Ep. 10 Sep 25, 2020

Explaining Signet - NADO 10

Sjors and Aaron discuss Signet, a new type of testnet for Bitcoin that was merged into Bitcoin Core last week. They also discuss the original version of testnet and its problems, as well as alternative testing environment regtest. Chapters 00:00:00 Opening and the test-network discussion 00:01:26 Why testnet is useful and unstable 00:05:00 Regtest for local automated testing 00:06:47 A predictable shared testing environment 00:08:04 Signet blocks combine signatures and proof of work 00:09:05 Default signers, custom signets and centralization 00:11:53 Testing and revising soft forks 00:13:29 Custom reorg tests, Lightning and release plans Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Music: Song Title: Segwit Sounds By: The NakamoTones Album: Citadel Music Produced by: Bitcoin Audio

25:18

Ep. 09 Sep 25, 2020

Schnorr Signatures and Libsec256k1 - NADO 9

Schnorr signature support was merged into the libsec256k1 library last week. In the episode of The Van Wirdum Sjorsnado, Aaron and Sjors discuss what the libsecp256k1 library is, why it matters for Bitcoin, and what it means that Schnorr signature support was merged. Sjors also briefly explains what he ultimate send RPC is, his own pull request that was recently merged into Bitcoin Core as well. Helpful Links: The Power of Schnorr: https://bitcoinmagazine.com/articles/the-power-of-schnorr-the-signature-algorithm-to-increase-bitcoin-s-scale-and-privacy-1460642496 Chapters 00:00:00 The send RPC, PSBTs and hardware-wallet integration 00:03:57 Schnorr support arrives in libsecp256k1 00:04:54 What is a software library? 00:05:50 Bitcoin dependence on OpenSSL 00:08:59 Signature parsing, BIP66 and consensus dependencies 00:12:28 A dedicated Bitcoin signature library 00:15:13 Reviewing cryptographic code and sharing the library 00:17:45 Implementing Schnorr on the same elliptic curve 00:20:07 Merged code, releases and eventual Taproot activation 00:23:01 Why Schnorr signatures are useful Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost

40:39

Ep. 08 Sep 25, 2020

Statechains w/ Ruben Somsen - NADO 8

Aaron and Sjors welcome their first guest on to the show, Ruben Somsen, to discuss his proposals for Statechains on Bitcoin! Statechains allow you to send keys not UTXO and it offers quite a few scaling and functionality improvements! Helpful Links: Ruben’s presentation on Bitcoin Magazine about Statechains: Aaron’s Bitcoin Magazine article on Statechains: https://bitcoinmagazine.com/articles/statechains-sending-keys-not-coins-to-scale-bitcoin-off-chain Chapters 00:00:00 Introducing Ruben Somsen and statechains 00:02:55 Off-chain transfers of whole UTXOs 00:06:15 Two keys and unilateral recovery transactions 00:11:15 Overriding old states with eltoo 00:13:01 Trusting the operator and reducing custody risk 00:18:57 Opening Lightning channels on statechains 00:20:49 Implementations before ANYPREVOUT 00:23:33 The state history and public double-spend detection 00:28:06 Scaling layers, adoption and federation tradeoffs 00:31:42 Payment pools, monitoring and nested designs Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost

24:38

Ep. 07 Sep 25, 2020

What is an XPub? - NADO 7

In this episode of the Van Wirdum Sjorsnado, Sjors and Aaron explain what an xpub is and how it is used by Bitcoin wallets. Helpful Links: http://rosenbaum.se/book/grokking-bitcoin-4.html#_hierarchical_deterministic_wallets https://walletsrecovery.org Chapters 00:00:00 The xpub controversy 00:03:08 Random wallet keys and the backup problem 00:04:51 BIP32 and deterministic master keys 00:06:52 Child keys, accounts and derivation paths 00:08:58 What an xpub reveals to a wallet server 00:11:10 Gap limits and missing wallet history 00:16:04 The lasting privacy cost of sharing xpubs 00:17:19 Seed words and BIP39 usability 00:20:55 Changing standards while preserving old backups 00:22:12 Wallet recovery needs derivation information too Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Music: Song Title: Segwit Sounds By: The NakamoTones Album: Citadel Music Produced by: Bitcoin Audio

35:54

Ep. 06 Sep 25, 2020

Payment Pools and Taproot - NADO 6

In this episode of the Van Wirdum Sjorsnado, Sjors and Aaron discuss the future of Bitcoin Scaling. This podcast is all about Taproot and the cool feature it enables called Payment pools. Topics What are payment pools? Why they need Taproot. The UX of sharing UTXOs How Payment pools work with lightningHelpful Links: https://bitcoinmagazine.com/articles/building-on-taproot-payment-pools-could-be-bitcoins-next-layer-two-protocol Chapters 00:00:00 Sharing a UTXO: payment pools and multisig 00:05:06 Presigned exits and payment channels 00:07:54 Taproot makes pools private and compact 00:09:15 Private payments, balances and pool membership 00:16:18 Off-chain updates and ANYPREVOUT 00:17:56 Hosting Lightning channels inside a pool 00:20:07 Unilateral exits and the factorial design problem 00:26:00 Splitting the exit tree into groups 00:28:20 Covenants, CTV and safer withdrawals 00:32:30 Implementation complexity and long-term scaling Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Music: Song Title: Segwit Sounds By: The NakamoTones Album: Citadel Music Produced by: Bitcoin Audio

54:02

Ep. 05 Sep 25, 2020

The Time-warp Soft Fork & Bitcoin Cash's Difficulty Adjustment Drama - NADO 5

In this episode of the Van Wirdum Sjorsnado, Sjors explains the “time-warp attack” on Bitcon and Aaron explains the unfolding drama with the bcash difficulty adjustment. Helpful Links: https://bitcoinmagazine.com/articles/miners-are-milking-bcashs-difficulty-adjustments-and-why-problem1 https://bitcoinmagazine.com/articles/why-bcash-mining-shouldnt-affect-bitcoin-much-bitcoin-mining-could-ruin-bcash https://read.cash/@jtoomim/dark-secrets-of-the-grasberg-daa-a9239fb6 https://blog.bitcoinabc.org/2020/07/23/announcing-the-grasberg-daa/ https://github.com/TheBlueMatt/bips/blob/cleanup-softfork/bip-XXXX.mediawiki Chapters 00:00:00 Block timestamps and difficulty retargeting 00:07:10 How the time-warp attack lowers difficulty 00:17:51 A proposed time-warp fix and consensus cleanup 00:23:18 Why the expected block interval is slightly off 00:25:23 Bitcoin Cash difficulty disputes: the background 00:29:15 Miner switching and the minority-chain problem 00:33:50 Emergency adjustment and mining the algorithm 00:38:54 Replacing the emergency adjustment 00:42:47 Fast retargeting and isolated-node security 00:44:52 ASERT, Grasberg and correcting historical drift Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Music: Song Title: Segwit Sounds By: The NakamoTones Album: Citadel Music Produced by: Bitcoin Audio

29:09

Ep. 04 Sep 25, 2020

What is Miniscript - NADO 4

In this episode of the Van Wirdum Sjorsnado, Aaron and Sjors dive into Miniscript and how it makes using Bitcoin Script much easier. Helpful Links: Chapters 00:00:00 Miniscript and Bitcoin spending conditions 00:03:34 A stack-based Script example 00:08:41 Why combining arbitrary scripts is dangerous 00:12:35 Miniscript templates and safe composition 00:14:23 Analyzing complex wallet policies 00:18:09 Policy languages express spending intentions 00:22:15 Compilers optimize transaction costs 00:23:46 Miniscript limitations and optional adoption 00:25:57 Minsc and practical wallet integration Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Music: Song Title: Segwit Sounds By: The NakamoTones Album: Citadel Music Produced by: Bitcoin Audio

44:12

Ep. 03 Sep 25, 2020

Breaking Down Taproot Activation Options - NADO 3

In the third episode of The Van Wirdum Sjorsnado, Aaron and Sjors break down and explain the different opinions and options available for activating Taproot and potentially future softfork upgrades. Helpful Links: Explainer article by Aaron discussing the different upgrade options: https://bitcoinmagazine.com/articles/bip-8-bip-9-or-modern-soft-fork-activation-how-bitcoin-could-upgrade-next Chapters 00:00:00 The Taproot activation debate 00:02:53 Soft forks, compatibility and flag days 00:06:38 Miner readiness signaling and BIP9 00:09:08 SegWit, BIP148 and BIP91 00:14:19 BIP8 and optional forced signaling 00:20:24 Modern Soft Fork Activation and a review pause 00:24:43 A one-year deadline and the ability to abort 00:27:11 Independent activation clients and early deadlines 00:33:37 Combining long windows with later activation pressure 00:38:26 Patience, review time and governance precedents Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Music: Song Title: Segwit SoundsBy: The NakamoTonesAlbum: Citadel MusicProduced by: Bitcoin Audio

31:02

Ep. 02 Sep 25, 2020

Explaining Taproot - NADO 2

In the second episode of The Van Wirdum Sjorsnado, Aaron and Sjors break down and explain Taproot, the building blocks that make Taproot possible, and what it enables Bitcoin to do. Helpful Links: Taproot Explainer: Chapters 00:00:00 Introducing Taproot and its building blocks 00:02:49 Pay to script hash and spending conditions 00:07:54 MAST and revealing only the script you use 00:12:18 The cooperative spending path 00:14:48 Schnorr signatures and combining keys 00:17:53 Taproot hides a script tree inside a key 00:23:03 Multisignatures and MuSig 00:25:09 Lightning privacy and larger contracts 00:28:37 Implementation, wallet readiness and activation Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Music: Song Title: Segwit SoundsBy: The NakamoTonesAlbum: Citadel MusicProduced by: Bitcoin Audio

35:19

Ep. 01 Sep 22, 2020

Explaining New PSBT and RBF Attacks - NADO 1

Bitcoin Magazine’s Technical editor Aaron van Wirdum teams up with Bitcoin core contributor Sjors Provoost to explain Bitcoin one episode at a time. In the debut episode of The Van Wirdum Sjorsnado, Aaron and Sjors break down and explain Partially Signed Bitcoin Transactions (PSBT) and Replace By Fee (RBF) and some really tricky attacks that where recently discovered in Bitcoin. Helpful Links: PSBT Attack Vector: RBF Attack Vector: Chapters 00:00:00 Meet the hosts: hardware wallets and excessive fees 00:06:49 SegWit commits signatures to input amounts 00:07:34 Combining signatures from two misleading requests 00:11:57 Checking previous transactions fixes the fee attack 00:13:01 Taproot and signing all input information 00:17:07 Wallet compatibility and mitigation tradeoffs 00:20:54 Replace by fee and the fee market 00:24:57 Opt-in replacement rules and miner incentives 00:27:45 Replacement handling, wallet balances and denial of service 00:32:14 Security reporting and the scale of the problem Support the Show! Follow Bitcoin Magazine on Twitter @BitcoinMagazine Follow Aaron van Wirdum @AaronvanW Follow Sjors Provoost @provoost Music: Song Title: Segwit SoundsBy: The NakamoTonesAlbum: Citadel MusicProduced by: Bitcoin Audio