In this conversation, Stephan Livera and Calle discuss the critical importance of privacy in financial systems, particularly in the context of Bitcoin and eCash. They explore the evolution of privacy technology, the challenges posed by current financial regulations, and the need for user-friendly privacy-preserving systems. Calle elaborates on the mechanics of eCash and the Cashu protocol, highlighting its potential for enabling microtransactions while maintaining user privacy. The discussion emphasizes the urgency of building a decentralized financial ecosystem that respects individual privacy rights.

Takeaways

🔸Privacy is essential for modern society and financial interactions.

🔸The fight for financial privacy is still in its infancy.

🔸Bitcoin serves as the foundational currency for the digital age.

🔸Technological advancements are crucial for enhancing privacy.

🔸Users should have control over their personal data.

🔸The current financial system often requires excessive data sharing.

🔸Privacy-preserving systems can be built using modern technology.

🔸Cashu offers a protocol for creating interoperable eCash wallets.

🔸Microtransactions are vital for a thriving internet economy.

🔸The future of financial systems must prioritize user privacy.

Timestamps:

(00:00) - Intro

(01:05) - What is Calle’s view on the current landscape of privacy & financial freedom?

(07:42) - What level of privacy is actually realistic?; Holding data ≠ Owning data

(15:16) - Building privacy-preserving systems on Bitcoin; Can privacy tech also be easy to use?

(21:09) - What is eCash & Cashu?; How does eCash work?

(30:15) - Why not just use Lightning?; eCash vs. Lightning Network & Ark

(37:43) - Will Lightning be the common language of future monetary transactions?

(40:46) - Cashu the protocol and eCash wallets

(43:00) - Who will be running the Cashu mints?

(43:26) - Sponsors

(49:39) - What are Stablenuts?

(53:20) - Can Cashu mints be rugged?

(55:59) - What’s next for Cashu and eCash?

(1:02:12) - Why is privacy necessary?

(1:06:35) - Closing thoughts

Links:

• https://x.com/callebtc

• https://x.com/CashuBTC

• https://github.com/callebtc

• https://wallet.cashu.me/welcome

Sponsors:

• Bold Bitcoin

• CoinKite.com (code LIVERA)

Stephan Livera links:

• Follow me on X: @stephanlivera

• Subscribe to the podcast

• Subscribe to Substack

In this conversation, Andrew Poelstra discusses the recent launch of Simplicity on Liquid, a federated sidechain of Bitcoin. He explains the technical aspects of Liquid, its advantages, and how Simplicity serves as a new scripting language that enhances expressivity and formal verification capabilities. The discussion covers potential use cases for Simplicity, including advanced covenant implementations, ZK verification, and its role in capital markets and asset issuance. The conversation also touches on the implications of stablecoins moving to their own chains and contrasts Liquid with other Layer 2 solutions like Lightning.

Takeaways

🔸Liquid is a federated sidechain of Bitcoin.

🔸Simplicity enhances Bitcoin's scripting capabilities.

🔸Formal verification improves security for developers.

🔸Simplicity allows for advanced covenant implementations.

🔸ZK verification can be done on Liquid.

🔸Liquid serves as a technology demo platform.

🔸Stablecoins are exploring their own chains.

🔸Liquid is not primarily a scaling solution for Bitcoin.

🔸Liquid supports multiple asset types.

🔸Simplicity can facilitate new financial products.

Timestamps:

(00:00) - Intro

(01:57) - What is Liquid?

(04:36) - What is Simplicity?; Enhanced expressivity on Bitcoin

(11:48) - Implications of ‘formal verification’ for developers building on Liquid and Bitcoin?

(17:00) - What does Simplicity enable people to build?

(18:59) - What is a Sighash flag?

(26:41) - Sponsors

(28:35) - Could Shielded CSV be built using simplicity?

(33:32) - Zero Knowledge proofs verification with Simplicity

(43:15) - Use cases of Simplicity: Limit orders and Algorithmic trading in DeFi

(51:18) - Liquid's role in asset issuance and capital markets

(56:55) - Liquid vs. Stablecoins issuing their own Layer 1 chains

(1:02:22) - Liquid vs. other Layer 2 solutions

(1:07:53) - Closing thoughts; Developer engagement with Simplicity

Links:

• https://simplicity-lang.org/

• https://blog.blockstream.com/simplicity-launches-on-liquid-mainnet/

• https://github.com/BlockstreamResearch/SimplicityHL/tree/master/examples

• https://github.com/BlockstreamResearch/SimplicityHL

Sponsors:

• Bold Bitcoin

• CoinKite.com (code LIVERA)

Stephan Livera links:

• Follow me on X: @stephanlivera

• Subscribe to the podcast

• Subscribe to Substack

In this episode, Stephan Livera and Calvin talk about Utreexo. They discuss the latest updates, including the publication of three BIPs related to Utreexo, which aim to improve the efficiency of Bitcoin nodes. The conversation covers the mechanics of Utreexo, including its accumulator structure and the concept of a Merkle forest. They also explore different types of nodes, such as compact state nodes and bridge nodes, and how these innovations can enhance user experience and participation in Bitcoin. Additionally, they touch on the growing Bitcoin community in Korea and the potential for future developments in the Utreexo space.

Takeaways

🔸Utreexo aims to improve Bitcoin node efficiency.

🔸The accumulator structure allows for compact representation of UTXOs.

🔸Merkle forest enables better management of UTXO sets.

🔸Compact state nodes simplify Bitcoin participation for users.

🔸Bridge nodes serve as intermediaries between Utreexo and traditional nodes.

🔸P2P communication is essential for Utreexo nodes.

🔸Floresta is a practical implementation of Utreexo concepts.

🔸UtreexoD serves as a reference implementation for developers.

🔸Community engagement is crucial for Utreexo's adoption.

🔸The Bitcoin community in Korea is rapidly growing.

Timestamps:

(00:00) - Intro

(00:50) - What is Utreexo?; Latest developments with Utreexo

(04:44) - Trust assumptions in Utreexo

(06:35) - Bridge nodes vs. Compact state nodes

(10:58) - What is the Utreexo accumulator?

(12:58) - What is a Merkle Forest?

(14:18) - Consensus operations in Utreexo; Utreexo validation

(18:02) - How does P2P communication work with Utreexo?

(19:15) - Sponsors

(23:22) - What is the Bridge node and why is it needed?

(25:27) - How do the Utreexo nodes find each other?; The future of Bridge nodes

(30:31) - What is Floresta?

(32:05) - What is UtreexoD?; Comparing it with Floresta

(34:45) - Community engagement with Utreexod & BTCD

(37:35) - What’s new with Bitcoin in Seoul, Korea?

Links:

• https://x.com/kcalvinalvinn

• Bitcoin Social Layer: https://exciting-cheek-5fa.notion.site/itcoin-Social-Layer-17267469618f80e78b4ec91ae055ec06

• https://x.com/btcsociallayer

• https://eprint.iacr.org/2019/611.pdf

• BIP Drafts: https://github.com/bitcoin/bips/pull/1923

• BIP

• Accumulator - https://github.com/utreexo/biptreexo/blob/main/utreexo-accumulator-bip.md

• Validation https://github.com/utreexo/biptreexo/blob/main/utreexo-validation-bip.md

• P2p https://github.com/utreexo/biptreexo/blob/main/utreexo-p2p-bip.md

• Mail list post:https://groups.google.com/g/bitcoindev/c/W1lxBraKG_E?pli=1

• Swiftsync: https://bitcoinops.org/en/newsletters/2025/04/11/#swiftsync-speedup-for-initial-block-download

• Utreexo: https://bitcoinops.org/en/topics/utreexo/

Sponsors:

• Bold Bitcoin

• CoinKite.com (code LIVERA)

Stephan Livera links:

• Follow me on X: @stephanlivera

• Subscribe to the podcast

• Subscribe to Substack