Security Model
Threat Model
Trusted Zone
Your Browser
Crypto
Encryption
Hashing
Key Derivation
User Data
Data stays local
Input: Text, Passwords, Files
Passwords
Files
External Zone
Server
No data access here
Network
No transmission
Third Parties
No data sharing
Security Assumptions
- • Your device is secure
- • Modern browser with Web Crypto API
- • Strong passwords
Limitations
- • Compromised device = risk
- • Browser extensions with broad permissions may access page content
- • We cannot recover lost passwords - encryption is mathematically irreversible
Security properties and explicit limitations of our client-side architecture.
Trust Assumptions
- Device free from malware
- Standard, up-to-date browser
- No compromised extensions
- Secure network (HTTPS)
- Understanding of crypto limitations
Explicit Limitations
- Does not protect against endpoint threats like keyloggers, clipboard monitors, or screen recording software.
- Cannot prevent you from accidentally sharing sensitive output (e.g., copying an encrypted token to an untrusted chat application).
- Assumes correct use of cryptographic parameters. The security of AES-GCM encryption, for example, relies on the user providing a strong, unique password.
- Does not provide authentication - anyone with the password can decrypt the data.
- Does not protect against replay attacks if encrypted data is captured and re-submitted.