BitCred

World's First Decentralized Credit Reputation Protocol Powered by Bitcoin

Inspiration

In traditional finance, credit scores are centralized, opaque, and inaccessible to large populations—especially in developing regions.
But in the Web3 world, we already have open financial activity on public ledgers. The question is:
Can we build a decentralized and privacy-preserving alternative to credit scoring?

This inspired us to create BitCred — a protocol that lets users prove their financial credibility using their Bitcoin wallet activity, without exposing any sensitive data.

What it does

BitCred analyzes a user's Bitcoin address and generates a credit reputation score using parameters like:

Wallet age and consistency
Volume and frequency of transactions
Historical activity patterns

Once calculated, the score is converted into:

A Zero-Knowledge Proof (ZKP) — ensuring privacy
A Verifiable Credential (VC) — in W3C-compliant format

The user can download this VC or share it with third parties like dApps, employers, or lenders.
Anyone can verify the score without needing access to the user's wallet or data.

How we built it

We used a combination of modern web tech and decentralized protocols:

Frontend: Next.js (App Router), Tailwind CSS, Shadcn UI, Recharts
Backend: Supabase (for Auth & Database), Vercel (for Hosting)
Blockchain Data: Rebar Labs API for real-time Bitcoin wallet metadata
ZK Proofs: circomlibjs for generating lightweight zero-knowledge proofs
Verifiable Credentials: JSON-LD spec for credential creation and validation

Workflow:

Users Need to Signup & verify their gmail via link sent on mail & then sign in.
User enters wallet address
Bitcoin metadata is fetched
Score is calculated
ZK proof is generated
VC is issued and downloadable

Challenges we faced

Data Modeling: Bitcoin wallets vary a lot in usage; scoring had to be fair, dynamic, and explainable.
Privacy vs Verifiability: Ensuring no wallet data leaks while maintaining provable trust.
ZK Integration: Keeping proofs small and compatible with real-time VC issuance.
Time: We had to prioritize the core functionality over stretch goals like DeFi integrations or DID wallets.

Accomplishments

Built a fully working decentralized credit scoring flow
Successfully issued W3C-compliant Verifiable Credentials
Enabled trustless verification using ZKPs
Created a clean, responsive, and minimal UI
Kept the solution simple enough to be adopted by real users and developers

What we learned

Applying zero-knowledge cryptography to real-world use cases
Building privacy-preserving products without compromising on usability
The strength of open blockchain data when used responsibly
Designing decentralized identity systems using VCs + DIDs

What’s next

Remove visible wallet address from credential (demo-only feature)
Integrate Lightning wallet support
Add score breakdown for transparency
Enable on-chain minting of credentials (Soulbound NFTs)
Collaborate with Web3

Built With

bitcoin
circom
git
github
ipfs
json-ld
next.js
node.js
op-return
react.js
snarkjs
tailwind
tailwindcss
vscode

Submitted to

Bitcoin 2025 Official Hackathon

Created by

This project BitCred was built entirely by me, as solo builder. I joined the hackathon after May 10 and honestly, I wasn’t even sure at first if I could finish something meaningful on time. But the idea of building a decentralized identity system on Bitcoin really excited me, so I decided to give it everything I had.

From day one, I started researching verifiable credentials, zk-SNARKs, and Bitcoin’s OP_RETURN—topics that were quite new to me. I went through a lot of trial and error, especially while writing Circom circuits and generating zero-knowledge proofs with SnarkJS. It was frustrating at times, but also incredibly rewarding when things finally worked.

I tried to handled everything smartly-

Designing the overall architecture,

Writing backend logic in Node.js,

Building a clean and usable frontend with React and Tailwind CSS,

Structuring credentials in JSON-LD,

Integrating Bitcoin OP_RETURN to anchor proof hashes,

And even experimenting with IPFS for decentralized storage, but used supabase for imediate work.

There were nights I barely slept, but I learned a lot—about cryptography, Bitcoin infrastructure, frontend/backend integration, and most importantly, how to push through when nothing seems to work.

This project really tested me, but also gave me a lot of confidence. It feels great to have turned a complex idea into something real, completely on my own.

Tafsir Raza
Anam Yusuf

Updates

Tafsir Raza started this project — May 20, 2025 02:26 PM EDT

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