The problem
Sensitive text and files are often shared through tools designed for permanent storage or ordinary collaboration. VaultFrost explored a narrower model: the sender controls how long a secret exists, how many times it can be opened, and what happens when that limit is reached.
A complete encrypted-sharing product
VaultFrost supported encrypted text notes and file uploads through controlled share links. A sender could apply time-based expiry, view limits, passwords, and self-destruct behavior. Paid plans added larger files, longer retention, branding, and account-level controls.
The product treated expired, revoked, invalid, password-protected, and exhausted links as intentional user experiences rather than generic server errors.
Security architecture
Content encryption used AES-256-GCM with PBKDF2-derived keys and separate handling for encrypted notes and files. The surrounding security model included:
- Passwordless magic-link authentication
- Short-lived login links and managed sessions
- Rate limits for authentication, creation, access, uploads, downloads, and administration
- Production content-security policy and secure cookies
- Plan-based file-size and retention enforcement
- S3-compatible object storage
- Scheduled removal of expired material
From secure feature to SaaS platform
VaultFrost was built beyond the share-link screen. It included four subscription tiers, Stripe checkout and webhook handling, account usage limits, branded shared links, transactional email preferences, a protected administration area, and a CMS for legal and policy pages.
Operational work included structured Better Stack logging, request diagnostics, database and object-storage health checks, branded Open Graph images, error boundaries, and an external status page.
Product boundaries
Some planned capabilities—multi-item secrets, API keys, user-facing analytics, and custom domains—were documented for later phases rather than presented as finished functionality. Recording that boundary was part of keeping product messaging aligned with what the platform could actually do.
Archive status
VaultFrost reached a functional, previously operational state, but its infrastructure has been taken down and the source repository remains private. This archived case study preserves the product, security, billing, and operational work without implying that visitors can currently create or retrieve secrets.