Hardware wallets are recommended universally, and the reasoning is frequently left implicit, which leads people to assume broader protection than they provide.
The threat model
The device keeps private keys in hardware that never exposes them to the connected computer.
Which protects against a compromised computer extracting keys.
That is the specific threat, and it is a real and common one.
What signing actually involves
The computer prepares a transaction, the device signs it, and the signature returns.
The key never leaves.
Which means a compromised computer can still present a transaction that is not what you intended.
Why the screen matters
The device screen shows what is being signed, independent of the computer.
Which is the entire defence against a compromised host substituting a different destination.
Approving without reading the device screen removes most of the benefit of having one.
Blind signing
Where the device cannot display what a transaction does, it may present opaque data.
Which is common with contract interactions and is where many losses have occurred.
Devices with better transaction parsing address this, and coverage is incomplete.
Approvals
Granting a contract permission to move tokens persists after the transaction.
Which means a malicious approval signed once can be used later.
Reviewing and revoking approvals periodically is a specific and underused practice.
The recovery phrase
The device protects the key from software, and the phrase reconstructs it entirely.
Which means the phrase is the actual secret and the device is a convenience around it.
Anything that photographs, types or transmits the phrase defeats the whole arrangement.
No legitimate service ever asks for it, and every request for it is fraudulent without exception.
Supply chain
Devices should be bought from the manufacturer or an authorised seller.
Which addresses tampering, and devices arriving with a pre-filled recovery phrase are a known scam.
A genuine device generates the phrase on first setup and never supplies one.
What it does not protect against
Approving a fraudulent transaction, losing the phrase, coercion, or sending to a wrong address.
Which are the causes of a large share of actual losses.
The device narrows one attack surface well and leaves the rest to the person operating it.
Passphrases
An additional secret combined with the recovery phrase produces a different set of accounts.
Which provides deniability and creates a new way to lose everything if forgotten.
It is not recorded on the device or in the phrase, so there is no recovery route.
Backup practice
The phrase should be recorded physically and stored where fire, flood and theft are all considered.
Which is why metal backups exist and why splitting across locations is common practice.
Schemes splitting a secret into shares, where a threshold reconstructs it, address single-point loss and add complexity.
Multisignature arrangements
Requiring multiple keys to authorise a transaction removes the single point of failure entirely.
Which is standard practice for organisations and is used by relatively few individuals.
The setup complexity and the risk of losing access to a threshold are the practical barriers.
Testing recovery
A backup that has never been tested is an assumption rather than a backup.
Which is worth verifying with a small amount before relying on it.
Recovery failures are generally discovered at the worst possible moment.
Inheritance
Assets held with keys nobody else knows are lost when the holder is.
Which is a genuine and underdiscussed problem, and various arrangements exist with different trade-offs between security and accessibility.
Firmware and updates
Devices receive firmware updates, and these should come through the manufacturer's own application.
Which is where verification of authenticity happens.
The recovery phrase should never be required during a routine update, and a request for it during one is a serious warning sign.
Address verification
Confirming a receiving address on the device screen rather than on the computer.
Which defends against malware substituting an address at the point of display.
Threat modelling
The appropriate arrangement depends on amount, on who might target you and on what you can operate reliably.
Which means the right answer differs between someone holding a small amount and an organisation holding a large one.
Complexity that is not maintained becomes a failure mode rather than a protection.
Practising
Running through a recovery on a spare device before it is needed removes most of the risk of getting it wrong.
Physical security
A device protected by a PIN resists casual theft, with wipe-after-attempts behaviour on most models.
Which means the device itself is not the secret, and the backup remains the thing to protect.
Storing device and backup in the same place removes much of the benefit of having both.
Summary
It narrows one attack surface well and leaves human judgement as the remaining one.
Common losses
Analysis of reported losses consistently shows approval abuse, phishing signatures and lost backups ahead of device compromise.
Which indicates where attention is best spent.
The device addresses the least common of these.