Capstone Project; Aask

🚀 Aask: Federated Document Sharing (Android)

90 App Builds, 260 Hours Later.

I was able to finish my federated document sharing app (only for Android as of now).

Sharing identity documents like passports, driver's licenses, and IDs is a necessary but risky part of modern life. Whether you're applying for a job ,renting an apartment, or verifying your identity with a service provider, you're often forced to send sensitive documents through insecure channels—email, messaging apps, or physical copies that can be lost, stolen, or misused.

📄 About Aask

Aask is a React Native mobile application that reimagines document sharing from the ground up. We combine cutting-edge technologies to create a system that’s secure by design.

🛠️ Technology Stack

The Aask document sharing application is built on a modern, secure, and decentralized technology stack:

• Mobile App: React Native + Expo is used for the cross-platform frontend, enabling deployment to both iOS and Android devices.

• Backend: Node.js + Express provides the robust foundation for the backend services, primarily hosting the REST API required for the mobile application.

• Database: MariaDB is utilized for metadata storage, specifically engineered to hold only encrypted metadata related to user accounts and shares.

• File Storage: Storj serves as the decentralized cloud storage solution, ensuring documents are split and stored across a global network for enhanced security and resilience.

• Blockchain: Polygon Mainnet is the choice for recording immutable share records, leveraging its low fees and fast finality for transparent auditing.

• Identity: Privado ID is integrated to handle the GDPR Compliant aspect covering the right to be forgotten/erased.

💡 How Aask Works

1. User Registration

• Automatically generates an Ethereum wallet.

• Private key is AES-256 encrypted, accessible only with the user's password.

2. Document Upload

• Computes SHA-256 hash for integrity.

• Uploads the file to Storj's decentralized network.

• Stores only metadata in the database.

• Document is never stored on centralized servers.

3. Secure Sharing

1. Generate unique AES-256 encryption key.

2. Download original from Storj.

3. Encrypt document with recipient-specific key.

4. Upload encrypted copy to Storj.

5. Record share on Polygon blockchain (immutable, timestamped proof).

6. Store share metadata with encryption key.

4. Recipient Access

• Encrypted file is downloaded and decrypted using the stored key.

• An audit trail entry is created (timestamp, IP, device info is logged).

5. Blockchain Verification

• Shares can be verified by anyone on PolygonScan using the transaction hash.

🛡️ Security Architecture

Encryption Layers

• At Rest: User private keys (AES-256), Documents on Storj (AES-256-GCM encrypted per-share), Database (Encrypted connections).

• In Transit: All API calls (HTTPS/TLS 1.3), Blockchain transactions (Cryptographically signed).

Decentralization Benefits

• Storj Decentralized Storage: Files split across a global network, no single point of failure, resistant to censorship, end-to-end encrypted.

• Polygon Blockchain: Immutable records, transparent and auditable, no central authority, permanent proof of sharing.

🎯 The User Experience

Aask is designed for simplicity:

1. Sign up with email and password.

2. Upload your documents (passport, license, ID).

3. Tap Share and select a recipient.

4. Done – Received instantly with blockchain verification.

Recipient Features

• View documents in-app.

• Verify authenticity on PolygonScan.

• See the complete audit trail.

⚙️ Why Polygon?

• Low Fees: Transactions cost fractions of a cent.

• Fast Finality: Confirmations in seconds.

• Ethereum Compatible: Battle-tested security.

• Environmental: Proof of Stake consensus.

🗺️ Future Roadmap

• Document Expiration: Time-limited shares.

• Selective Disclosure: Share only specific fields.

• Multi-signature: Require multiple approvals.

• Enterprise Additions: Organization management

• Qr Code Functionality: Add QR code functionality for document sharing.

📝 Conclusion

Aask represents a new paradigm for document sharing—one where users maintain control, every action is auditable, and trust is established through cryptography.

Your documents. Your control. Verified on the blockchain.