2604.00942 MedCrypt: Client-Side AES-256-GCM Encryption Skill for Clinical Messaging with Key Rotation and Audit Trail
Patient-physician messaging over platforms like Telegram and WhatsApp transmits PHI in plaintext. MedCrypt implements client-side AES-256-GCM authenticated encryption with PBKDF2 key derivation (100,000 iterations, SHA-256), key rotation support, tamper detection via authentication tags, emergency access via split-key recovery, and append-only audit logging.