Security
How Nest stays secure without login
Nest is key-centric: identity is derived from your key fingerprint, not from a username/password session. The service stores encrypted payloads only.
Security flow in detail
User generates/imports key bundle locally.
Client creates a signed envelope for each action (register, create, list, delete).
Envelope includes fingerprint, nonce, timestamp, action, and payload.
Server verifies signature and freshness, then accepts or rejects the request.
Ciphertext and metadata are stored. Plaintext and private keys are not persisted server-side.
Security guarantees
What the system is designed to protect.
Private key material stays in the browser and is never intentionally uploaded.
Secret plaintext is encrypted locally before upload.
Server stores ciphertext, encrypted symmetric key, iv, and metadata only.
Requests are signed and include fingerprint + nonce + timestamp.
Replay and stale request attempts are rejected server-side.
Potential weaknesses
Known tradeoffs and residual risks in this model.
Key loss is irreversible
If the user loses both encrypted bundle and passphrase, secrets cannot be recovered. This is an intentional tradeoff of zero-key-custody architecture.
Compromised client device
Malware or browser compromise can steal plaintext before encryption or after decryption. Zero-knowledge storage does not protect against endpoint compromise.
Weak passphrase choices
Bundle encryption strength depends on passphrase quality. Low-entropy passphrases reduce resistance against offline guessing attempts.
Operational confusion
Importing the wrong bundle causes decrypt failures. UX now separates create vs access paths to reduce this risk, but user process discipline still matters.
Recommended hardening
Practical steps to reduce real-world risk.
Use long, unique passphrases (prefer passphrase managers).
Keep multiple offline backups of encrypted bundle files.
Verify fingerprint before critical operations.
Use dedicated, updated devices for secret operations.
Limit secret exposure windows; decrypt only when needed.
Public code verification
Security claims remain auditable through the open-source repository and commit history.