Security & self-custody
Self-custody makes you the sole master of your funds — and the only one responsible. No customer service to reverse a transaction, no password to reset. The five non-negotiable principles, the attacks actually observed in the wild, the EAL scale and a self-audit to place your own level in two minutes.
The fundamentals
Everything else follows from them. If these five points are respected, almost every loss-of-funds scenario observed in the ecosystem becomes powerless against you.
These 12 or 24 words regenerate all of your private keys, on any device, anywhere in the world. Whoever holds them holds your funds. Never type them into a computer or a phone, never photograph them, never store them in a password manager. No support team, no manufacturer, no service will ever ask you for them.
The PIN protects physical access to the device: it stops whoever steals it. The passphrase (the “25th word”) derives an entirely separate wallet from the same seed: it protects your funds even if your seed phrase is discovered. The trade-off: a forgotten passphrase is unrecoverable, exactly like a lost seed.
Malware is able to replace the destination address at the moment you copy and paste, without changing anything in your browser display. Only the hardware wallet screen, driven by signed firmware, shows the address that is actually signed. Compare at least the first six and the last six characters, on every send, including small amounts.
Paper burns, gets wet and fades. Prefer an engraved or stamped steel plate. Spread it across two physically distinct locations, neither of which is your office. Keep the passphrase somewhere other than the seed. And above all: test the restore at least once a year on a blank device — a backup that has never been tested is not a backup.
Security patches only work once they are installed. Download exclusively from the manufacturer's official sources, never from a link received in a message or found in an advertisement. Check the signature or the fingerprint whenever one is published, and back up before any major update.
Risk overview
The attacks that succeed rarely target the cryptography. They target the user, their inbox, their parcel or their computer. Every threat below has a simple countermeasure.
Pixel-perfect cloned sites and apps, fake support, hijacked QR codes. A formidable variant: the attacker sends you a zero-value transaction from an address that looks like yours, so that you copy it back from your history.
FixType URLs by hand, never copy an address from your history, check it on the device screen.The attacker has your number transferred to their SIM card, intercepts SMS codes and takes control of your exchange accounts. Often preceded by a call from “technical support” to gather information.
FixReplace SMS-based 2FA with a physical key or a TOTP app. Never approve anything during an incoming call.Infected browser extensions, pirated software, monitored clipboard. The goal: to make you blind-sign a transaction whose real destination you have not read.
FixA dedicated machine, or at least a separate browser profile, zero non-essential extensions, systematic refusal of blind signing.A device opened and modified before it reaches you, or worse: delivered with a “recovery card” already filled in. A new wallet never contains a pre-generated seed.
FixBuy from the manufacturer or an authorised reseller, inspect the seals, always generate a fresh seed yourself.Someone gets a few minutes with your device or your backup: a hotel room, a shared office, a rented flat. No visible trace, the attack triggers later.
FixPassphrase enabled, device and backups kept out of sight, visual check of the seals on your return.An unknown token appears in your wallet and invites you to “claim” it on a website. The signature requested does not send tokens: it grants an unlimited spending allowance.
FixIgnore unsolicited tokens, read what you sign, revoke granted allowances regularly.Rule with no exception: nobody — not Neowalt, not a manufacturer, not an exchange — has any legitimate reason to know your seed phrase. A single request of this kind is enough to identify a scam.
Hardware security
The Evaluation Assurance Level measures how rigorously a component has been evaluated, according to the international Common Criteria standard. The scale runs from 1 to 7; the “+” suffix indicates strengthened requirements beyond the base level.
Most hardware wallets rely on a Secure Element certified EAL5+ or EAL6+. One important nuance: the certification covers the chip, not the entire device. A high EAL is an excellent signal, but real security depends just as much on the firmware, on the product architecture — and on your own practices. A badly used EAL6+ protects you less than a well-used EAL5+. Compare the levels model by model →
Self-audit
Twelve points, two minutes. Tick only what is true today — not what you intend to do. The score updates live and stays in your browser: nothing is sent, nothing is recorded on our side.
Not every item carries the same weight: the seed phrase backup counts for more than the rest, because it is the only element that nothing can recover once it is gone. 🔒 Score calculated and kept in your browser — no data leaves your device.
On arrival
A supply chain compromise plays out before your very first transaction. Here is the protocol to follow between opening the parcel and your first outgoing transfer.
Seals intact, original packaging, a legible and matching serial number, all accessories present. No pre-filled recovery card should be inside the box: its mere presence disqualifies the device. If in doubt, do not set it up and contact the seller.
Download the official app from the manufacturer's site, typed in by hand — never from a sponsored result or a link you were sent. Check the file's hash or signature whenever one is published, then let the device verify the authenticity of its own firmware.
Generate a fresh seed phrase on the device, never anywhere else. Write the words down away from onlookers and cameras, on a durable medium. Enable the passphrase if you know how to manage it. Finish with a test transfer of a token amount before moving anything significant.
Backups & inheritance
The overwhelming majority of funds lost for good were not lost to a hacker, but to a single backup that was destroyed, forgotten or impossible to pass on. Choose the setup you will genuinely still know how to operate in five years.
The baseline, within everyone's reach. Seed phrase in two separate places, passphrase in a third. None of the three is your main home alone.
The seed phrase is split into shares, a subset of which is enough to rebuild it (2 of 3, for example). It spreads trust without multiplying points of failure.
Several independent devices must sign in order to spend (2 of 3, 3 of 5). The standard for large amounts — it demands genuine operational discipline.
A sealed file: an inventory of holdings, restore instructions, contacts, a named executor. The seed phrase is never in it — only the path that leads to it.
Emergency plan
In these three situations, speed matters more than perfection. Act in order, and treat any potentially exposed key as permanently compromised.
Glossary
A sequence of 12 or 24 words (the BIP39 standard) that regenerates all your private keys. To be kept offline, always.
An extra word or phrase that derives a separate wallet from the same seed phrase. It protects you if the seed phrase is discovered — but forgetting it means losing the funds.
Data exchange with no direct connection, typically by QR code. It removes the USB and Bluetooth attack surfaces.
Several independent keys are required to spend (2 of 3, 3 of 5). No single device is a point of failure.
The seed phrase is divided into N shares, of which M are enough to rebuild it. It distributes trust with no single complete copy.
A hardened, certified chip that stores the keys and resists physical attacks. It is the chip, not the whole device, that the EAL certification measures.
Frequently asked questions
Certification level, connection type, battery life, compatibility, backup handling: our comparison tool puts these criteria side by side across the whole range, so that your choice follows from how you actually use a wallet rather than from a marketing sheet.
Educational content. It replaces neither your own checks, nor your internal policies, nor your regulatory obligations. Never disclose your seed phrase, to anyone, under any circumstances.
