The Spanish Red Cross (Creu Roja) has introduced RedChain, a blockchain-based system for distributing humanitarian aid that aims to give donors real-time transparency while safeguarding recipients’ identities. Developed with Barcelona infrastructure provider BLOOCK and zero-knowledge credential specialist Billions Network, the platform digitizes the full aid lifecycle from allocation to redemption.
Instead of paper vouchers or prepaid cards, RedChain issues ERC-20 aid credits on the Ethereum network. Recipients receive credits in a mobile wallet and redeem them at participating merchants via QR codes. All personal beneficiary records—names, contact information and case files—remain offchain in Creu Roja’s internal systems. The public blockchain is used only as a verification layer, anchoring hashes, timestamps and integrity proofs of transactions rather than storing any personal data.
Donors and administrators can audit when and where funds are allocated and spent through aggregated, verifiable onchain proofs, but the system prevents anyone from reconstructing individual identities from those records. Creu Roja says donors will be able to see program-level distributions and timing, while beneficiaries’ identities and circumstances remain confidential. The design prioritizes transparency of flows and outcomes without exposing or commodifying vulnerable people’s personal data.
Creu Roja frames RedChain as a response to pressure on humanitarian organizations to demonstrate that aid reaches its intended purpose without turning recipients into data sources. Project lead Francisco López of Creu Roja Catalunya emphasized that people seeking assistance should not have to trade their privacy for help. Transactions using the digital credits are processed like ordinary purchases, avoiding visible markers that would single out aid recipients. Creu Roja also says the system is built to avoid excluding people who have limited technical access.
RedChain uses a hybrid trust model: ERC-20 tokens represent allocated aid onchain, while spending records and eligibility checks remain in offchain databases linked to cryptographic proofs on the blockchain. BLOOCK describes its role as providing a certification layer—cryptographic anchors on a public ledger that make unauthorized modifications to internal records detectable without publishing the underlying data. BLOOCK CEO Lluís Llibre explained that anchoring each relevant state change to a public chain means later tampering with internal records would not match the immutable onchain proofs, effectively serving as a public notary.
Billions Network supplies the zero-knowledge credential component, letting beneficiaries demonstrate eligibility or authorization without revealing identity or private attributes. Those proofs are held in the user’s wallet rather than a central registry, preserving privacy while enabling verifiable access to aid.