How Tempest Protects Your Privacy
Tempest uses zero-knowledge end-to-end encryption — your SSH keys and passwords are encrypted on your device before sync. We cannot read them.
What that means in practice
The cryptography
Layer
Algorithm
Purpose
Tempest uses zero-knowledge end-to-end encryption — your SSH keys and passwords are encrypted on your device before sync. We cannot read them.
Tempest is built on zero-knowledge end-to-end encryption (E2EE). Your SSH keys, passwords, snippets, and connection metadata are encrypted on your device before anything is uploaded for cloud sync — meaning we couldn't read them even if compelled to. This is the same security model that 1Password, Bitwarden, and Signal use.
You hold the only key that can decrypt your data — your vault password, which never leaves your device.
Tempest's servers see only ciphertext. We sync it between your devices but cannot read it.
If you forget your vault password, your data is unrecoverable. We don't have a backdoor and we can't make one. See Reset Your Tempest Password.
Key derivation
BLAKE2b
Stretches your vault password into a symmetric key
Symmetric encryption
xsalsa20poly1305 (authenticated encryption)
Encrypts each record before sync
Transport
TLS 1.3
Protects the wire between your device and Tempest sync servers
Sync conflict resolution
Multi-master replication over encrypted blobs
Lets multiple devices stay in sync without the server seeing plaintext
The crypto layer will be open-sourced so anyone can audit it.
A small amount of operational metadata is necessarily plaintext on our servers:
Your sync account email (so we can sign you in)
Document IDs and revision counters (so the sync engine can replicate)
Approximate document sizes (limit enforcement)
We never see hostnames, usernames, passwords, key contents, snippet text, or any other connection detail.
Monitoring data is parsed locally inside your Tempest tab and is never sent anywhere — not even to your other devices via sync. It's a render-only feature.
AI requests are sent to the model provider you've configured (OpenAI, Anthropic, Google, or your self-hosted endpoint). Tempest acts as a transport — we don't proxy or log the requests. You can also point Tempest at a fully local model.
Reset Your Tempest Password — sync vs. vault passwords explained
SSH Cert Storage — short-lived certs are stored as paths, not contents, when possible