Security
Key principles
- The starting sentence (12/24 words) = master key . Never type it on a computer/phone.
- The PIN protects access to the wallet, the passphrase protects the seed.
- Check the address on the device screen before each sending.
- Offline backups in two separate locations, regular restore testing.
- Update firmware & apps from official sources.
Objective: to reduce your physical, software and social attack surfaces.
Physical security: EAL (Evaluation Assurance Level) levels
Many wallets use a Secure Element certified EAL5+ or EAL6+ . A high EAL (End-of-Average Level) = more assurance, but actual security also depends on the firmware and design. and your usage practices.
Your security score
Common threats
- Phishing / address poisoning : cloned sites/applications, similar addresses, malicious QR codes.
- SIM swap & social engineering : 2FA/SMS takeover and manipulation.
- Malware / keyloggers : blind signatures, infected extensions.
- Supply chain : device damaged before receipt, "pre-printed" seed.
- Evil-Maid : stealthy physical access (office/hotel).
⚠️ Red flags
Essential good practices
- Initialize the wallet yourself, from official sources .
- 6+ digit PIN ; disable auto unlocking of mobile phones.
- Passphrase : activate it to compartmentalize.
- Seed on steel , 2 separate locations, never photographed.
- Verify addresses on your device . Avoid public Wi-Fi.
- Regular firmware /application updates. Back up before any update.
- For large amounts: opt for multisig (2/3) or Shamir.
Receiving: Supply chain control
1) At the opening
- Sealed intact, official packaging, no pre-filled "seed card".
- Numbers/serial numbers visible, accessories as described.
2) Installation
- Download the official application (Ledger Live / Trezor Suite / dedicated app).
- Check the fingerprint or signature if available.
3) Initialization
- Generate a new seed on the device.
- Activate the secret phrase if you know how to manage it.
- Write your words down on a durable medium (steel recommended), in private.
Backups and legacy
- 2 separate locations for the seed; secret phrase elsewhere .
- Shamir : M-on-N sharing (e.g., 2/3) to distribute trust.
- Multisig : several devices/keys required (e.g. 2/3).
- Legacy : sealed file (inventory, instructions, contacts), designated executor.
Choose between Shamir and Multisig depending on your operational capacity.
Personal Policy Generator
Emergency plan (incident)
Loss/theft of the device
- Restore on a new device in a safe location (seed + passphrase).
- Transfer the funds to new keys immediately.
Potentially exposed seed
- Immediately move all funds to a new seed/passphrase.
- Consider multisig/Shamir.
Suspected malware/phishing
- Disconnect, isolate the machine, change passwords offline.
- Reinstall cleanly or use a dedicated, clean machine.
Quick Glossary
Starting sentence
A 12/24 word sequence, BIP39, which allows you to regenerate all your keys. Keep offline.
Passphrase
An additional word/phrase that creates different portfolios. Don't forget it.
Interfer
Streaming without a direct connection (e.g., QR code). Reduces USB/Bluetooth risks.
Multisignature
Several keys needed for spending (e.g., 2/3). Ideal for large amounts.
Shamir
Sharing the seed into fragments (M-on-N) to distribute trust.