Meetup # 10 – March 9, 2023 Meetup # 10 – March 9, 2023

2 Agenda Agenda Mission: “Our mission is to share bitcoin knowledge, tools, and resources creating a peer to peer network of local bitcoiners within the Round Rock community.” Purpose Our purpose is to grow bitcoin adoption by individuals and small businesses in a circular economy within our local community. Location(s): - Lamppost Coffee 6-7PM - BrassTap – 7- ??? Rules: No shitcoining No pictures/video unless we agree ahead of time Chatham house – speakers should not be attributed Announcements: OshiApp Lamppost Gift Cards The Bitcoin Company Honey Badger – Free Sats! Circular Economy (Satoshi Square) - Azteco Vouchers Bitcoin Magazine Sponsorship – 50% Off Bitcoin 2023 & The Bitcoin Games - Miami BTCPayserver for Donations Stickers from MVDEX & Lucho Poletti Questions: Who has made an on-chain bitcoin transaction? Who has made a lightning transaction? Who is running a bitcoin full node?

3 Connect to our node Connect to our node 02dd5649b3b872024e6c9cac775fdea95f08c05a5fa9575e96e214b6a90baed438@z7wmavvxd irafksqhm2mwmfvujymsfzwyf7tzitmrzfgn6fynn2fioqd.onion:9735 Open a channel with us and we will open one with you

4 Donate some sats to our BTCPayserver Donate some sats to our BTCPayserver Goes to paying for our meetup costs and outreach

5 Connect w/ us on Twitter @RBitcoiners Connect w/ us on Twitter @RBitcoiners Give us a follow!

6 Find Us on NOSTR Find Us on NOSTR NIP-05 ID: roundrockbitcoiners@nostrplebs.com NIP-05 ID: roundrockbitcoiners@nostrplebs.com Npub17ysayggwumkpkpgsq75axd7ed9guw03wz9jldz5d0zrkgz0cja2qd09tzu wss://nostr.roundrockbitcoiners.com Is this the real Web 3.0?

7 We have a new website! We have a new website! https://roundrockbitcoiners.com Many thanks to Julie!!!

8 Onboarding Local Businesses Onboarding Local Businesses What local businesses are currently accepting bitcoin?

9 Onboarding Local Businesses Onboarding Local Businesses The problem What are some potential solutions?

10 Onboarding Local Businesses Onboarding Local Businesses - Existing - Existing Opportunities Opportunities Ask a local business if they accept bitcoin ● Never hurts to ask! ● Some businesses are struggling with credit card processing fees for small transactions (Can be 1.5 – 3.5% of each transaction). ● A good way to build a business treasury for future expansion. Just ensure they understand the long-term nature of their hodlings. Farmer George Market ● Round Rock: Saturdays between 10AM – 2PM ● Behind Ikea Wolf Ranch Farmers Market ● Georgetown: Saturdays between 10AM – 2PM ● Wolf Ranch Shopping Center Other Farmers Markets ● The Market at Indian Mound Ranch (Saturday, March 19th 9 am – 1 pm) 12805 SH 29 W Liberty Hill, TX ● Texas Farmer’s Market at Lakeline: (Saturdays 9 am – 1 pm) 11200 Lakeline Mall Drive, Cedar Park, TX ● Wilco Farmer’s Market: (Thursdays from 10 am -2 pm) E 8th St, Georgetown, TX 78626 ● Eli’s Roadside Produce (Open Everyday) Many food trucks that we can onboard Can you think of any others?

11 Onboarding Local Businesses Onboarding Local Businesses Oshi App Oshi is a powerful marketing and rewards platform built to replace stars, punch cards, and coffee points with something that people really want - Bitcoin. IbexPay IBEXPAY is the easiest and fastest way for any business to accept instant Bitcoin payments over the Lightning Network and On-Chain. Whether you are a single location over the counter taco shop or a multinational clothing chain with many managers and locations, IBEXPAY can work for you. Open Node Get lightning-fast, low-cost bitcoin payments and payouts for your business with our powerful API, ecommerce plugins, or hosted payment pages. Strike Send and receive money instantly. Buy bitcoin. Get paid in bitcoin. Cash App The easy way to buy, sell, send, and receive bitcoin What other payment tools can businesses use?

12 What are some other ways to find local What are some other ways to find local businesses that accept bitcoin? businesses that accept bitcoin? Oshi App local map ● Lists all the locations that are currently accepting bitcoin via the Oshi App. ● Some businesses only have gift card options to purchase. BTCMap ● Open source project that uses OpenStreetMap to tag places where you can spend bitcoin. ● Much of the data is outdated, so please help verify! Do you know of any other good resources?

13 And now for a bit more technical topic: And now for a bit more technical topic: Swaps between Cashu mints Swaps between Cashu mints “Swaps between cashu mints are great for increasing privacy from an LN observer's perspective. First understand that as long as transactions are done with Cashu tokens within the same mint or between mints via swaps, privacy is perfect. In transactions within the mint itself, the mint does not know with whom the tokens are being exchanged, and in swaps between mints the receiving mint also does not know the origin of the swap, since the transaction is launched by the LN node where the first mint is located, and not by the user. Finally, there is the case of wanting to exchange the token in the second mint. In this case the LN node where the mint operates performs a transaction towards our wallet or LN node, but from the point of view of an LN observer, if we use different wallets or nodes between the first mint (sending over LN to create the token) and the second one (redeeming the token through LN) there is no traceability. Therefore, we can use swaps between mints to erase the traceability of our satoshis at a ridiculous cost since we only pay LN fees and you can add as many hops between mints as you want to add obfuscation. I add a small diagram to make it clearer.”

14 Swaps between Cashu mints Swaps between Cashu mints By using 2 separate nodes, we can get perfect privacy

15 What is Cashu? What is Cashu? Cashu is the protocol; Nutstash a wallet

16 What is Cashu? What is Cashu? Based on David Chaum’s Blinded Signature Technology Cashu is a free and open-source Chaumian ecash system built for Bitcoin. Cashu offers near-perfect privacy for users of custodial Bitcoin applications. Nobody needs to knows who you are, how much funds you have, and with whom you transact with.

17 What is Chaumian eCash? What is Chaumian eCash? David Chaum is associated with the invention of Blind Signature Technology. In 1982, while studying at the University of California, Berkeley, Chaum wrote a paper describing the technological advancements to public and private key technology, in order to create this Blind Signature Technology.[4] Chaum's Blind Signature Technology was designed to ensure the complete privacy of users who conduct online transactions. Chaum was concerned with the public nature and open access to online payments and personal information. He then proposed to construct a system of cryptographic protocols, in which a bank or the government would be unable to trace personal payments conducted online.[5] This technology became fully implemented in 1990, through Chaum's company, DigiCash.

18 What is Chaumian eCash? What is Chaumian eCash? 3 main characteristics of Chaumian eCash (1) Inability of third parties to determine payee, time, or amount of payments made by an individual. (2) Ability of individuals to provide proof of payment, or to determine the identity of the payee under exceptional circumstances. (3) Ability to stop use of payments media reported stolen.

19 Some Wizardy: Sending and receiving blinded Some Wizardy: Sending and receiving blinded signatures (exercise) signatures (exercise) Chaumian eCash tokens - payer bank to payee’s bank

20 How To Send ECash Tokens To Nostr Users How To Send ECash Tokens To Nostr Users 1. Create wallet 2. Add a mint 3. Configure Nostr https://wallet.nutstash.app/

21 How To Send ECash Tokens To Nostr Users How To Send ECash Tokens To Nostr Users Successful receive over Nostr! https://wallet.nutstash.app/