Public institutions still rely heavily on paper documents containing personal information, leading to environmental costs, security risks, and limited traceability. This study proposes “KiWi,” a secure information request and management system that digitizes paper-based processes. KiWi combines QR-code-based public-key exchange, ECDH key agreement, and AES-256-GCM encryption. Sensitive data are stored only in the iPhone Keychain, while the server handles encrypted transfers without accessing plaintext information. Our system enables secure digital submission of personal data, improves traceability, and reduces paper consumption in institutional workflows.