Show HN: An encrypted, local, cross-platform journaling app
Mini Diarium is a new encrypted, local, and cross-platform journaling app built with Rust, Tauri, and SolidJS. It emphasizes robust privacy and user control, featuring AES-256-GCM encryption, unique key file authentication, and zero network access. Hacker News was drawn to its deep technical design, open-source ethos, and solutions for data longevity and security, even sparking debate on cryptographic best practices and data portability.
The Lowdown
Mini Diarium presents itself as a privacy-focused, cross-platform journaling application, serving as a spiritual successor to the unmaintained Mini Diary. The developer's core philosophy centers on keeping entries encrypted locally with no internet connectivity, ensuring data remains on the user's machine. The app boasts a modern tech stack, leveraging Tauri 2, SolidJS, and Rust for a lighter, faster experience with enhanced encryption.
Key features include:
- AES-256-GCM Encryption: All entries are encrypted with a random master key, with authentication methods holding wrapped copies for efficient management.
- Key File Authentication: Alongside traditional password protection, users can unlock their diary with an X25519 private key file, similar to SSH keys, providing flexible and multi-factor authentication options.
- Zero Network Access: The app explicitly states no telemetry, analytics, or update checks, prioritizing user privacy.
- Rich Text Editor & Calendar Navigation: Standard journaling functionalities are included.
- Import/Export Capabilities: Supports importing from Mini Diary, Day One, and jrnl, and exporting to JSON and Markdown, addressing concerns about data portability and vendor lock-in.
- Cross-platform Support: Available for Windows, macOS, and Linux, with planned mobile support.
- Automatic Backups: Features rotation for backups on unlock.
Mini Diarium's design prioritizes strong, standardized encryption and local data storage, giving users full control over their journal without reliance on cloud services. Its open-source nature and detailed architecture diagrams appeal to those seeking transparency and security in personal data management.
The Gossip
Data Durability & Decentralization Debates
Commenters explored the long-term accessibility and future-proofing of journal data. Some advocated for plain-text or Markdown files in an encrypted folder (e.g., via Cryptomator) for maximum future compatibility, while others defended SQLite with client-side encryption as a robust and feature-rich compromise. The developer confirmed that export to JSON or Markdown is supported, addressing concerns about vendor lock-in and allowing users to leave the platform at any time. There was also discussion on syncing the local SQLite file to cloud storage, which the developer acknowledged as possible and plans to simplify.
Cryptographic Considerations & Security Schemas
The technical aspects of Mini Diarium's encryption scheme drew significant attention. Concerns were raised about plaintext data being swapped to disk by the OS and potential future needs to evolve encryption algorithms. One suggestion involved separating key-wrapping (KEK) from data encryption (DEK) layers, similar to LUKS, to facilitate easier cryptographic upgrades without re-encrypting the entire dataset. The developer's implementation of multiple authentication slots (password + key file) was praised for mitigating the risk of losing access due to a forgotten password or compromised key.
Alternative Apps & Platform Predicaments
Users compared Mini Diarium to existing solutions like Obsidian (often combined with tools like CryFS or Rclone for encryption/sync) and other dedicated journaling apps. A common sentiment was the appeal of a simple app doing one thing well, even if other tools offer broader functionality. A recurring critique was the lack of mobile platform availability, as many users prefer journaling on their phones, though the developer confirmed plans for Android and potentially iOS support.
Aesthetic Appreciation & README Revelations
There was notable positive feedback on the project's presentation and user interface. Commenters lauded the "fancy" and detailed README.md, including its clear architectural diagrams. The app's minimalist yet pretty UI also received praise. A minor suggestion involved embedding a proper video in the README instead of a GIF for better quality and user control.