Security You Control — Ciphertext Only

MyColdKey never stores or transmits a readable seed phrase, password, or note.

Everything is encrypted locally on your device before it ever leaves your machine.

What you store is always ciphertext.

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Your data stays encrypted. Encryption and decryption happen locally on your device.

You recover with your encrypted backup + password — no MyColdKey servers required.

Your control, by design

What actually protects you when it matters most.

You Own Your Recovery

Offline recovery with your encrypted backup and password. No login required.

The Self-Contained Recovery Kit you export works completely standalone on any air-gapped machine.

Sovereign Mode (Pro)

Keep server access off by default. You control when (if ever) the app briefly connects.

30-minute access windows are in-memory only and clear on restart.

Encrypted on Your Device

Argon2id + AES-256-GCM happens locally. Plaintext never leaves your machine.

Cloud+ stores ciphertext only — we never see your vault password or data.

How MyColdKey fits into your protection strategy

Redundant encrypted copies

Add encrypted copies alongside your hardware wallet and existing backups. You hold the only keys.

Air-gapped recovery

Recover offline on an air-gapped machine with the free recovery tools or the Self-Contained Recovery Kit.

One layer for all secrets

Works for seed phrases, passwords, keys, and notes — one consistent recovery model.

Portable encrypted copies

Encrypted QR copies can be physically distributed or stored anywhere — they reveal nothing without your password.

Threat model + limits

What this protects you from — and what it does not.

Protects you from

  • Stolen backup copies (ciphertext only)
  • Device loss or failure
  • Vendor disappearance
  • Cloud provider breach (Cloud+ is also ciphertext)

Does not protect you from

  • Weak or reused passwords
  • Physical coercion or compromised local device
  • Human error (losing your password)

How encryption works on your device

All encryption happens locally using Argon2id key derivation + AES-256-GCM authenticated encryption + HMAC-SHA256 tamper detection. Your password never leaves your device. Plaintext never touches disk or the network.

Encrypt on your device
Local-first encryption before anything is saved or exported
Store encrypted backup
QR, file, text, or recovery shares — unreadable without your password
Recover offline
Use your encrypted backup and password — no login required

Activation

Standard online activation fits most setups. Air-gapped import with Sovereign Mode fits maximum isolation.

Standard activation (online)

  • Sign in once to link and restore your license on this device.
  • Recovery still runs completely offline with your encrypted backup and password.

Air-gapped activation

  • Purchase where you have connectivity, then import the license file on the offline machine.
  • Often combined with Sovereign Mode for long-running offline use.

Verification

GitHub Releases include installers, standalone offline decrypt tools, and checksums.txt (SHA-256). You can always verify the binaries before installing.

The Self-Contained Recovery Kit you export from the app includes offline recovery tools and step-by-step instructions.

See offline recovery tools

Password hygiene

Your password is the key to recovery. Treat it like a recovery-critical secret.

FAQ

What if MyColdKey is unavailable?
Your encrypted backups stay fully usable without our servers. Recover with the Self-Contained Recovery Kit or the standalone offline tools from GitHub — only your encrypted backup and password are required.
Do I need to log in to recover?
In-app recovery works offline after one sign-in. The Self-Contained Recovery Kit works completely standalone — no login, no servers, and no company required, ever.
What if I lose the password?
Recovery requires your password. If lost, the encrypted backup remains encrypted. Store your password separately from your backups according to your threat model.
Can I test recovery before trusting it?
Yes. Create a test encrypted backup and recover it fully offline with the Self-Contained Recovery Kit. Once confident, repeat with your real data.
How many layers protect my data?
Local Argon2id + AES-256-GCM authenticated encryption, HMAC tamper detection, memory clearing, and optional Shamir shares. Plaintext never leaves your device.

Backed by open-source verification tools on GitHub. Checksums provided. You control the keys — always.

See pricing Offline recovery guide