š Security & Encryption
Your notes are protected with industry-standard end-to-end encryption. Only you can read them.
Security Overview
End-to-End Encryption
Notes are encrypted on your device before being uploaded. We cannot read your data.
Zero-Knowledge Architecture
Your encryption keys never leave your devices. Even we can't decrypt your notes.
No Metadata Leakage
Note titles, labels, and content are all encrypted. Only timestamps are visible.
Open Source Crypto
We use well-audited cryptographic libraries. No custom "security through obscurity".
Technical Details
Cryptographic Algorithms
- Symmetric Encryption: AES-256-GCM for note content
- Key Derivation: PBKDF2 with SHA-256, 100,000 iterations
- Key Exchange: X25519 (Curve25519 ECDH)
- Digital Signatures: Ed25519 for device verification
- Random Number Generation: Platform-native CSPRNG
Key Management
Your encryption keys are generated on your device and never transmitted to our servers.
- Master Key: Derived from your account credentials using PBKDF2
- Device Keys: Unique keypair generated per device
- Note Keys: Random symmetric key per note, encrypted with your master key
- Recovery Key: Optional 24-word mnemonic for account recovery
How End-to-End Encryption Works
1. You Write a Note
Your note exists only in memory on your device.
2. Local Encryption
A unique AES-256-GCM key is generated. Your note is encrypted with this key.
3. Key Encryption
The note's key is encrypted with your master key (derived from your credentials).
4. Secure Upload
Only encrypted data is sent to our servers over TLS. We never see plaintext.
5. Sync to Other Devices
Your other devices decrypt using your master key. Notes are readable only by you.
PIN-Protected Notes
Locked notes add an additional layer of encryption on top of the standard E2EE. When you lock a note with a PIN:
- The note content is encrypted with a key derived from your PIN
- This encrypted content is then encrypted again with your master key for sync
- The PIN never leaves your device or gets stored anywhere
- If you forget your PIN, the note cannot be recovered (by design)
What We Can See vs. Cannot See
What We CAN See (Metadata)
- Your email address (for authentication)
- Timestamps of when notes were created/modified
- Encrypted blob sizes (how big encrypted notes are)
- Device information (for multi-device sync)
- Aggregate usage statistics (anonymized)
What We CANNOT See
- Note titles
- Note content (text, checklists, etc.)
- Labels/tags
- Colors
- Attachment contents (images, files)
- Anything inside your notes
Account Recovery
Because we use true end-to-end encryption, we cannot reset your encryption keys if you lose access. That's why we provide a recovery key when you set up E2EE.
Recovery Key
Your recovery key is a 24-word mnemonic phrase that can restore access to your encrypted notes. Store it somewhere safeāif you lose both your device access and recovery key, your encrypted notes cannot be recovered.
Our Security Practices
- Regular audits: We regularly review our cryptographic implementation
- Dependency updates: Security patches are applied promptly
- Open source: Our encryption code is open for inspection
- No telemetry: We don't collect analytics on your note content
- Secure infrastructure: Firebase/GCP with SOC 2 compliance
- TLS everywhere: All data in transit is encrypted