@ HRF

In the summer of 2023, the Human Rights Foundation (HRF) launched a Bitcoin Bounty program aimed at funding software developers to create new tools and features for Bitcoin tailored to the needs of dissidents and human rights advocates challenging authoritarianism worldwide. These bounties ranged from UX improvements to privacy upgrades and open-sourcing closed and permissioned systems. There were 11 bounties in total, each with specific objectives. The deadline was Dec. 31, 2024. We are excited to announce that every single bounty was claimed and that the resulting tools and upgrades are now empowering human rights activists daily across popular apps such as Blue Wallet, Zeus, Stack Wallet, Iris, Coracle, Keeper, Bull Bitcoin, Cake Wallet, and more. This program highlights the impact of collaboration between human rights activists and software developers to create better tools for freedom. HRF is proud to have played a role in this effort and looks forward to continuing similar programs in the future. Special credit goes to the Oslo Freedom Forum, where much of the critical interaction between developers and activists occurred. This wave of bounties was inspired by a successful pilot project in 2021, executed in partnership with Strike and Jack Mallers, which supported developers like Will Cassarin and Calle. Their innovations later gave rise to important advancements such as zaps in Nostr and the Cashu ecash protocol. # **Bounty Details** #### **1. Open-Sourcing the Design Guide** **Winner:** [CypherStack](https://cypherstack.com/) for porting the Bitcoin UI Kit from Figma to an [open-source Penpot project](https://github.com/cypherstack/bitcoin-ui-kit-penpot) (2 BTC awarded). Many UI kits are created using proprietary software like Figma. While these tools are powerful, they require licenses and are not accessible to everyone — an obstacle for developers working on open-source projects or those with limited funds. This creates a barrier to entry for designers and developers wanting to contribute to the Bitcoin ecosystem. This bounty was awarded to CypherStack for porting the Bitcoin UI Kit from Figma to Penpot, an open-source design tool similar to Figma, but free and accessible to everyone. This helped democratize access to information and resources, promote collaboration, and make it easier for developers to create high-quality Bitcoin tools, which in turn helped to increase Bitcoin adoption. #### **2. Serverless Payjoin** **Winners:** This is a two-part bounty. The first bounty is for the development of the Serverless Payjoin specification, and the second bounty is for any wallets that implement Serverless Payjoin. **Part 1:** [Dan Gould](https://crates.io/users/DanGould) for his work on [PayJoin V2](https://crates.io/crates/payjoin-cli/) (1 BTC) **Part 2:** Dan Gould, [Spacebear](https://github.com/spacebear21) from Payjoin DevKit, and [Bull Bitcoin](https://www.bullbitcoin.com/) app, for their collaborative effort implementing Payjoin into the Bull Bitcoin wallet (0.5 BTC split three ways). PayJoin is a privacy upgrade to Bitcoin that flusters mass surveillance attempts on the network. Traditional implementations have required the receiver to run a server for transaction coordination, creating a barrier to adoption. Serverless PayJoin removed this dependency and simplified the process. Serverless PayJoin also eliminated the need for receiver-hosted infrastructure and reduced censorship risks by removing a central point of failure — a significant advantage for activists and nonprofits operating under repressive regimes. This bounty resulted in the first mobile app ([Bull Bitcoin](https://play.google.com/store/apps/details?id=com.bullbitcoin.mobile&hl=en_US)) with integrated PayJoin send and receive support, an important advancement that provided robust privacy protections against surveillance for at-risk individuals. #### **3. End-to-End Encrypted Nostr Group Chats** **Winners:** [Martti Malmi](https://iris.to/sirius) for incorporating encrypted group chat functionality into the [Iris](https://iris.to/) Nostr client (1 BTC) and to Vitor Pamplona, hodlbod, and Paul Miller for their work on NIP-17, which allowed users to encrypt and share Nostr messages in a way that can be recognized across different Nostr clients (1 BTC). End-to-End Encrypted (E2EE) Nostr Group Chats are private, secure messaging groups built on the Nostr protocol, a decentralized communication system. While Nostr messages are already encrypted, they still expose metadata, allowing outside observers to see who is communicating and when. This bounty focused on preventing metadata leakage, ensuring that these details remain private. By leveraging Nostr’s decentralized architecture, these chats offered censorship resistance. They prevented conversations from being surveilled, blocked, or controlled by a central authority, and as a result of this bounty, have now been implemented into popular Nostr clients like Iris, Amethyst, and Coracle. This is an important step forward for activists, journalists, and communities who risk losing their freedom of speech under oppressive regimes. #### **4. Silent Payments** **Winners:** [cygnet3](https://github.com/cygnet3) and [Sosthene](https://github.com/Sosthene00) for their contributions to [critical libraries](https://github.com/Sosthene00/electrs/tree/sp_tweaks) for delivering Silent Payments and for developing a [mobile wallet](https://github.com/cygnet3/danawallet) capable of sending and receiving Silent Payments without requiring a full node (1 BTC). Silent Payments are a privacy-enhancing Bitcoin addressing scheme that allows a sender to generate a unique static address for a recipient without requiring any interaction (while still allowing the recipient to detect and spend the received funds). This breaks common tracking methods used by surveillance firms and autocracies and makes it harder to link payments to a specific recipient. By improving on the privacy of traditional Bitcoin addresses, Silent Payments enhanced financial privacy, making them ideal for donations, salaries, and other sensitive transactions. This bounty code has been fully integrated into Cake Wallet, and several other major wallets like Wasabi, Blue Wallet, and Bitbox have added partial functionality. This brings Silent Payments to tens of thousands of users and marks a major step in real-world Bitcoin privacy. #### **5. Human-Readable Offers** **Winners:** [Stephen DeLorme](https://x.com/StephenDeLorme), [Chad Welch](https://x.com/chdwlch), and [Evan Kaloudis](https://x.com/evankaloudis) for [Twelve Cash](https://twelve.cash/) and its integration into [Zeus Wallet](https://zeusln.com/) (1 BTC). Human-Readable Offers simplify Bitcoin payments by replacing complex Bitcoin addresses and invoices with user-friendly text. This is especially important for Lightning Network transactions, which currently involve a cumbersome process of generating invoices for each payment. With Human-Readable Offers, sending Lightning payments becomes as simple as sending an email (just by entering a username). This approach, similar to many fintech apps today, reduces errors, lowers the barrier to entry, increases trust, and is crucial for broader adoption of Bitcoin among new and seasoned users alike. It’s also important for people who don’t have access to smartphones and cannot copy and paste or use QR codes. Today, as a result of this bounty, Zeus users connected to a Core Lightning node can create a human-readable Bolt 12 offer to privately receive donations. #### **6. Self-Custodial Mobile Lightning Address** **Winner:** Evan Kaloudis for [Zeus Wallet](https://zeusln.com/) (1 BTC). Activists, nonprofits, and content creators often use Lightning addresses to receive donations quickly and easily. However, setting up and managing a Lightning address presents a challenge: users have to choose between the self-sovereignty of managing their own web server (a complex process) or the convenience of a custodial service, which requires trusting a third party with their funds. This bounty directly addressed this issue. It allowed users of Zeus Wallet, one of the most popular self-custodial Bitcoin Lightning wallets, to easily and securely receive donations through a Lightning address while maintaining control of their funds. #### **7. Mobile Border Wallets** **Winner:** [Bitcoin Tribe](https://twitter.com/BitcoinTribe_) for their border wallet functionality, allowing users to create and memorize seeds without relying on written backups, and for building a [React Native library](https://github.com/bithyve/react-native-border-wallets), making it easier for other wallets to integrate this feature (2 BTC). Mobile Border Wallets aimed to solve a critical problem with traditional Bitcoin seed phrase backups: they’re often written down on paper, making them susceptible to being lost, destroyed, or stolen. This makes securing a user’s Bitcoin a delicate balance between security and accessibility. It also makes it challenging, especially for activists or refugees who frequently cross international borders. Border Wallets offered a solution to this problem. Instead of writing down a 12- or 24-word seed phrase and finding a secure place to store it, users can upload a randomly generated grid of words to the cloud and memorize a pattern to secure their seed phrase, similar to a pattern a user would memorize and draw on an Android device to unlock it. This initiative resulted in a user-friendly mobile app that allowed users to create Border Wallets digitally, enhancing accessibility and offering an alternative to physical storage like printed paper or metal seed plates. #### **8. Easy Mobile Multisig** **Winner:** [Bitcoin Keeper](https://bitcoinkeeper.app/) (1 BTC). Multi-signature wallets allow multiple users to collaboratively control a Bitcoin wallet. This enhances security by requiring consensus before funds can be moved. Traditional multisig wallets often require physical hardware wallets or involve subscription fees, presenting a significant barrier for organizations exploring Bitcoin adoption. This bounty funded the development of easy mobile multisig functionality in the Bitcoin Keeper app, enabling users to set up a 2-of-3 multisig (requiring two out of three keys to authorize spending) to secure and manage their bitcoin. This is a great feature for activists to prevent government seizure of funds: even if one key holder gets detained, the funds are safe so long as the other two key holders are safe. The idea is to make sure two of the keys are held by entities outside of one’s country or threat zone. #### **9. FROST Multisig Wallet** **Winner:** [CypherStack](https://cypherstack.com/) for [Stack Wallet](https://stackwallet.com/), which enables dynamic multisig using FROST, allowing users to modify signer sets without moving funds (1 BTC). Multisig (multisignature) wallets require multiple signatures to authorize a transaction. This enhances security by distributing control over funds. However, traditional multisig setups — while secure — can be inflexible. If you need to change the set of signers, it often requires moving all the funds to a new multisig wallet with the updated signer set. This is burdensome, time-consuming, and incurs fees. FROST is a cryptographic protocol that offers significant advantages for multisig wallets. It provides dynamic multisig functionality, meaning users can easily adjust their signer sets as needed without affecting the funds within. This is an important functionality for nonprofits and civil society groups who often need to adjust their authorized signatories, especially in situations where a regime may seize a private key and that key then needs to be deprecated. This dynamic kind of secure setup is now available for activists to use on the Stack Wallet. #### **10. Cashu Upgrades** Winners: [eNuts Wallet](https://www.enuts.cash/) (0.5 BTC), [Misovan](https://github.com/misovan) for [Minibits Wallet](https://www.minibits.cash/) (0.5 BTC), [Gandlaf](https://www.gandlaf.com/about) for [Proxnut](https://proxnut.com/) (0.5 BTC), and Gandlaf for adding [Cashu-TS restore](https://github.com/cashubtc/cashu-ts) functionality (0.5 BTC). Cashu is a digital cash system designed for privacy and speed. It is like physical cash, but in digital form and uses blind signatures for private transactions. With Cashu, transactions are instant, low-fee, and can operate offline. There is no blockchain or transaction graph to be surveilled. Bounty recipients addressed critical aspects of usability and accessibility for Cashu tools: eNuts and Minibits Wallets brought Cashu to iOS and Android users worldwide, Proxnut enabled easy web integration for payments, and Cashu-TS Restore added crucial seed phrase backup. Together, these projects have taken Cashu from a more theoretical concept to a practical one and have been relevant for use cases like donations, content monetization, daily transactions, and cross-border payments. #### **11. BIP47 Expansion** Winner: [Blue Wallet](https://bluewallet.io/) (0.5 BTC) for adding BIP 47 support. BIP47 is a Bitcoin Improvement Proposal that enhances payment privacy for Bitcoin users. In Bitcoin, it’s generally considered bad privacy practice to reuse the same Bitcoin address for multiple transactions. It can link those transactions together and make it easier to track a user’s spending in high-risk environments. Generating a new address for each payment has become a common workaround, but this becomes cumbersome. BIP47 solves this with reusable payment codes. Users receiving funds generate a BIP47 payment code and share it with those who will be sending them payments. Each time a payment is initiated, a new, unused Bitcoin address is generated from the recipient’s payment code. This ensures every transaction uses a unique address. Blue Wallet received this bounty for integrating BIP47 support, making this important privacy enhancement accessible to its growing user base. *HRF’s Financial Freedom program educates activists worldwide, unites people from different industries and backgrounds, and makes grants in the service of advancing Bitcoin as a tool for human rights. To receive HRF’s weekly Financial Freedom Report, subscribe [here](https://mailchi.mp/hrf.org/financial-freedom-newsletter).* *For media inquiries or interview requests, please contact media @ hrf.org.*