Security
How Filarr protects your data: KEK/FEK encryption architecture, local-first with zero-knowledge cloud sync.
KEK / FEK Architecture
Filarr uses a two-level key system. Each file is encrypted with its own File Encryption Key (FEK) using AES-256-GCM. All FEKs are themselves encrypted by a Key Encryption Key (KEK), derived from your password via PBKDF2. If one FEK is compromised, only that file is exposed — not the rest of your data.
Local-first, zero-knowledge
All encryption and decryption happens on your machine. Your keys never leave your device. When cloud sync is enabled, only encrypted blobs are stored on our servers (Cloudflare R2, EU). We cannot read your files — this is true zero-knowledge encryption.
Threat Model
Since your plaintext data never leaves your machine, Filarr’s threat model is fundamentally different from a typical cloud service. The main threats are physical access to your device or losing your password.
- Physical access to deviceProtected by AES-256-GCM encryption
- Password lossRecoverable via recovery phrase only
- Malware on deviceKeys in memory only during use
- Disk theftData unreadable without password
- Brute force attackPBKDF2 with high iterations
What this means in real life
Encryption is only useful if it protects you in the situations that actually happen.
Your laptop gets stolen
Your files are encrypted with AES-256-GCM. Without your vault password, they’re unreadable — even with full disk access. The thief gets an encrypted hard drive, not your documents.
A cloud provider gets breached
Filarr only stores encrypted blobs on our servers. Your files are encrypted on your device before upload. Even if our storage is compromised, attackers get unreadable ciphertext — not your files.
A legal request for your data
If Filarr receives a legal request, we can only hand over encrypted blobs. We don’t hold your encryption keys — we genuinely cannot decrypt your files. This isn’t a policy — it’s a technical fact.
You forget your vault password
This is the real cost of zero-knowledge. Your encryption key is derived from your password — if you lose it, we cannot recover your data. We recommend using a password manager and exporting a recovery key from Settings > Security.
What if Filarr gets curious?
We can’t. Your files are encrypted with a key derived from your password using PBKDF2-SHA-512 with 600,000 iterations. This key never leaves your device. Our servers only see random-looking bytes.
Your internet goes down mid-session
Filarr is local-first. Everything works offline — notes, files, graph, canvas. Changes sync automatically when you reconnect. No internet required to access your own files.
Multi-profile isolation
Each profile in Filarr has its own set of encryption keys. Data in a “Personal” profile is completely isolated from a “Client A” profile. Even if one profile is compromised, the others remain protected.
What we’re still working on
Cloud sync is live with end-to-end encryption — your files are encrypted on your device before upload. The code is currently in a private repo; an independent security audit is on our roadmap. We document our encryption architecture in detail so you don’t have to trust us blindly. There’s no SOC2 or HIPAA certification yet.