Encrypted Assignment Dispatch

This feature directly addresses a critical operational need identified by Norges Blindeforbund: the secure dispatch of sensitive personal data (including medical summaries and home addresses) to peer mentors in the field. Without this capability, organizations resort to unencrypted email or verbal handoffs, creating GDPR exposure and audit risk. By providing a purpose-built encrypted channel with read receipts and automatic reminders, the platform reduces compliance overhead and gives coordinators confidence that assignments are acted on promptly. From a business value perspective, the feature also strengthens the platform's competitive positioning for health-adjacent volunteer organizations, where data protection requirements are non-negotiable. The read receipt and status tracking capabilities reduce coordinator follow-up calls, freeing staff time for higher-value activities. Delivery confirmation also provides an evidentiary record for any disputes about whether a peer mentor received an assignment, reducing organizational liability.

Encryption should use asymmetric cryptography: each peer mentor has a keypair, with the public key stored on the server and the private key stored only in the device's secure enclave (iOS Secure Enclave / Android Keystore). Assignment content is encrypted with the recipient's public key before storage; the server never holds the plaintext or the private key. On the Flutter side, use the platform secure store via flutter_secure_storage, and invoke native crypto APIs for key generation and decryption. The assignments and assignment_reads tables track delivery and read state. Push notifications trigger on new assignment dispatch without including any sensitive content in the notification payload - only an assignment ID that the app uses to fetch and decrypt locally. The automatic reminder logic runs server-side as a scheduled job checking assignments older than the configured threshold with no read record. All encryption operations must be covered by integration tests with known key fixtures; UI must block screenshots on the assignment detail screen on both iOS and Android.