Security

zopp is built on a zero-knowledge architecture where the server never has access to your plaintext secrets.

Sections

• Architecture - Understand how zopp's zero-knowledge encryption works
• Cryptography - Deep dive into the cryptographic primitives used by zopp

Zero-Knowledge Design

zopp's core security principle: the server never sees plaintext.

Data	Client	Server
Secret values	Plaintext	Ciphertext only
Workspace KEK	Plaintext	Wrapped (encrypted)
Environment DEK	Plaintext	Wrapped (encrypted)
Private keys	Plaintext	Never sent
Invite secrets	Plaintext	Hash only

Security Properties

Confidentiality

• All secrets are encrypted with XChaCha20-Poly1305 before leaving your machine
• Keys are wrapped using X25519 ECDH, so only intended recipients can decrypt
• The server cannot decrypt any stored data

Integrity

• AEAD (Authenticated Encryption with Associated Data) detects tampering
• Ed25519 signatures authenticate all requests
• Workspace/project/environment names are bound to secret encryption

Access Control

• RBAC with three levels: workspace, project, environment
• Three roles: read, write, admin
• Principals (devices) can be individually revoked
• All access is logged in the audit trail

Key Management

• No master key or recovery key exists
• If a user loses their device keys, they lose access (by design)
• Workspace access is cryptographically enforced, not just policy

Threat Model

What zopp protects against

Threat	Protection
Server compromise	Attacker gets only encrypted data
Database leak	Secrets remain encrypted
Network interception	TLS encryption + E2E encryption
Malicious insider (server)	Cannot decrypt without client keys
Unauthorized access	RBAC + cryptographic enforcement

What requires additional protection

Threat	Mitigation
Client device compromise	Secure your device; use OS disk encryption
Phishing for credentials	User education; don't share ~/.zopp/config.json
Supply chain attacks	Verify binary signatures; build from source

Security Best Practices

1. Enable TLS - Always use HTTPS in production
2. Use strong passphrases - For any password-derived keys
3. Limit production access - Use environment-level permissions
4. Audit regularly - Review zopp audit list output
5. Rotate secrets - Update compromised credentials promptly
6. Backup safely - Encrypted backups only

Reporting Vulnerabilities

If you discover a security vulnerability, please email security@faisca.dev with:

1. Description of the vulnerability
2. Steps to reproduce
3. Potential impact

We'll respond within 48 hours and work with you on coordinated disclosure.

Next Steps

• Architecture - How zero-knowledge encryption works
• Cryptography - Cryptographic details