Security Model

zod-vault uses a zero-knowledge architecture. The server cannot read your data.

Threat Model

Protected Against

• Server compromise — Data is encrypted, server has no keys
• Database leaks — Only encrypted blobs stored
• Man-in-the-middle — HTTPS + client-side encryption
• Unauthorized access — JWT auth + user isolation

NOT Protected Against

• Client-side compromise — Malware on user’s device
• Recovery key theft — If someone has your key, they decrypt
• Weak recovery keys — Always use generateRecoveryKey()

Encryption

Algorithm: AES-256-GCM

• 256-bit key size
• Authenticated encryption (integrity + confidentiality)
• NIST approved, widely audited
• Web Crypto API (native browser/Node.js)

Key Derivation: Argon2id

• Memory-hard (resistant to GPU/ASIC attacks)
• OWASP 2024 recommended parameters:

memory: 64 MB
iterations: 3
parallelism: 4
hashLength: 32 bytes

Data Flow

┌─────────────────────────────────────────────────┐
│                   CLIENT                         │
│                                                 │
│  Recovery Key + Salt → Argon2id → AES Key      │
│                           ↓                     │
│  Plaintext → AES-256-GCM → Encrypted Blob      │
│                                                 │
└────────────────────────┬────────────────────────┘
                         │ HTTPS
                         ▼
┌─────────────────────────────────────────────────┐
│                   SERVER                         │
│                                                 │
│  Stores: { blob, salt, metadata }               │
│  Knows: NOTHING about your data                 │
│                                                 │
└─────────────────────────────────────────────────┘

What the Server Stores

Data	Encrypted?	Notes
User email	No	Needed for login
Password hash	Hashed	Argon2id
Vault data	Yes	Opaque blob
Vault salt	No	Useless without key
Timestamps	No	For sync

What the Server Cannot Do

• Read vault contents
• Recover data without recovery key
• Decrypt even with database access
• Impersonate users

Authentication

JWT Tokens

• Access token: 15 min expiry
• Refresh token: 7 day expiry
• Unique jti claim (no replay)
• Refresh rotation

Password Hashing

Argon2id
memory: 64 MB
iterations: 3
parallelism: 4

Passkeys (WebAuthn)

• Hardware-backed
• Phishing-resistant
• Recommended over passwords

Audit

The crypto is ~300 lines of TypeScript:

git clone https://github.com/nicodlz/zod-vault
cat packages/crypto/src/*.ts | wc -l

Uses:

• Web Crypto API (native, no custom crypto)
• hash-wasm for Argon2id (audited WASM)

Reporting Vulnerabilities

Found an issue?

1. Do not open a public issue
2. Email: ndlz@pm.me
3. Include: description, steps, impact

Response within 48 hours.