--- title: "What Is a Hardware Wallet and How Does It Work? (Ledger, Trezor)" url: "https://bip39-phrase.com/hardware-wallets-explained/" language: "en" published: "2025-07-29T00:00:00+00:00" updated: "2026-10-19T00:00:00+00:00" --- [ Wallets ](/topics/wallets/) Published July 29, 2025 Updated October 19, 2026 # What Is a Hardware Wallet and How Does It Work? (Ledger, Trezor) Читать по-русски: [Аппаратный кошелёк: что это и как работает](/ru/apparatnyj-koshelek/) ![Diagram: the app sends an unsigned payment to the hardware wallet, the device shows the amount and address, you confirm, and the key never leaves it](/images/blog/hardware-wallets-explained-hero.webp) A hardware wallet is a small, dedicated device that creates and stores the private keys to your crypto and signs transactions inside itself, so the keys never reach your internet-connected computer or phone. The coins stay on the blockchain: the device holds only the keys that can move them, and its own screen and buttons let you check each payment before it is signed. Ledger and Trezor are the best-known makers; Keystone, COLDCARD, BitBox, Blockstream, Foundation and Tangem build them too. This guide covers how the device works, how it is backed up and what it cannot protect you from. To pick a model, see [Ledger, Trezor and other hardware wallets compared](/hardware-wallet-comparison/). ## At a Glance | Question | Short answer | | ----------------------------- | ---------------------------------------------------------------------------------------------------- | | What does it store? | Your private keys, usually as a seed made from a 12- or 24-word recovery phrase. Never the coins. | | How does it make a payment? | Your wallet app prepares the transaction, the device shows it, you confirm, and the device signs it. | | What if you lose it? | Nothing is lost if you have the recovery phrase: you restore it on a new device. | | What does it protect against? | Malware on your computer or phone copying your keys. | | What can’t it stop? | A stolen recovery phrase, a payment you approve without checking, a tampered device. | | Who needs one? | Anyone holding more than they could afford to lose in a phone app or on an exchange. | ## What Does a Hardware Wallet Store? A wallet never holds coins. Balances are recorded on the blockchain, and a wallet keeps the keys that prove you may spend them. A hardware wallet keeps those keys in its own memory instead of on a general-purpose computer. Trezor puts it plainly: the device stores your private keys, not your assets, and your wallet backup can open the same funds on another device ([Trezor](https://trezor.io/learn/basics/what-is-a-hardware-wallet)). Most devices start from a single secret. During setup the device generates random numbers and encodes them as a recovery phrase, most often of 12 or 24 words as defined by the [BIP39 standard](https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki). The phrase becomes a seed, and the seed becomes a whole tree of keys: one branch for each coin and account. That is why one device can hold Bitcoin, Ethereum and other coins at once, and why the words alone can rebuild all of it. [What a seed phrase is](/recovery-seed-phrase-guide/) explains the format, and the [BIP39 visualizer](/how-bip39-works/) shows how random bits turn into words. ## How Does a Hardware Wallet Sign a Transaction? The device itself never goes online. It works with a companion app on your computer or phone, such as Ledger Wallet, Trezor Suite or a third-party wallet, which knows your public addresses and talks to the network: 1. **The app builds the transaction.** You enter the address and the amount, and the app prepares an unsigned transaction. 2. **It passes the transaction to the device** over a USB cable or Bluetooth, or as a QR code or a file on a microSD card. 3. **The device shows the details on its own screen**: the receiving address, the amount and the fee. 4. **You confirm on the device** with its buttons or touchscreen, after unlocking it with your PIN. 5. **The device signs inside itself** with your private key and returns only the signed transaction. 6. **The app broadcasts it.** A signed transaction can’t be changed on the way, so the computer can’t redirect it. Ledger describes the same flow and adds that the screen on its devices is driven directly by the secure chip, so it shows the real destination even when the computer is infected ([Ledger](https://www.ledger.com/academy/topics/ledgersolutions/how-ledger-hardware-wallets-work)). Step 3 is the point of the whole device: if the address on its screen is not the one you meant, cancel. Receiving needs no device at all, because addresses come from public keys the app already knows. BitBox notes that its device has to be connected only to sign and to show a receiving address for you to check ([BitBox](https://support.bitbox.swiss/en%5FUS/basics/bitbox02-keep-device-plugged-in-transactions)). Make that check before you share an address: malware on a computer or phone can change the address shown there, and a match with the device’s screen confirms the payment will reach your own wallet ([Trezor](https://trezor.io/guides/trezor-devices/trezor-fundamentals/trezor-s-trusted-display-verify-every-address-on-your-device)). ### Cable, Bluetooth, QR Code or microSD? Whatever the link, it carries only unsigned and signed transactions, never the keys. Air-gapped devices never connect for data at all: the [Keystone 3 Pro](https://keyst.one/shop/products/keystone-3-pro), the [COLDCARD Q](https://coldcard.com/start/q-vs-mk5/) and [Jade Plus](https://blockstream.com/jade/jade-plus/) scan QR codes with a camera, and all three can also pass files on a memory card. For Bitcoin they exchange Partially Signed Bitcoin Transactions, a format defined in [BIP174](https://github.com/bitcoin/bips/blob/master/bip-0174.mediawiki) that holds everything a signer needs. Bluetooth adds convenience rather than key exposure; on the Safe 7, for instance, Trezor encrypts every command with its open-source Trezor Host Protocol and lets you switch Bluetooth off ([Trezor](https://trezor.io/trezor-safe-7)). ## What Is a Secure Element, and Does Every Device Have One? A secure element is a tamper-resistant chip of the kind used in bank cards and passports, designed to keep its secrets even when an attacker probes it or glitches its power on a lab bench ([Ledger](https://www.ledger.com/academy/topics/ledgersolutions/how-ledger-hardware-wallets-work)). Most hardware wallets keep the keys in one. Ledger’s devices use chips certified to Common Criteria EAL5+ or EAL6+ ([Ledger](https://shop.ledger.com/pages/hardware-wallets-comparison)), Trezor’s Safe models an EAL6+ secure element ([Trezor](https://trezor.io/compare)), COLDCARD two secure elements from different vendors ([COLDCARD](https://coldcard.com/q)) and Keystone three ([Keystone](https://keyst.one/shop/products/keystone-3-pro)). Blockstream’s Jade has none on purpose: decrypting the phrase it stores takes your PIN, a device secret and a secret held by a “blind oracle” server, and after three wrong PINs both the device and the oracle delete their part ([Blockstream](https://help.blockstream.com/blockstream-jade/faq)). The trade-off is openness. Secure elements rely on chip makers’ proprietary designs, which is why Ledger publishes its apps and libraries but keeps closed the parts of Ledger OS that work directly with the chip ([Ledger](https://www.ledger.com/academy/topics/ledgersolutions/what-is-ledger-recovery-key)). Trezor publishes its firmware and, on the Safe 7, added TROPIC01, a secure element whose design it calls fully auditable, next to a conventional one ([Trezor](https://trezor.io/trezor-safe-7)). Open code lets outsiders check what a device does; a certified chip makes it harder to pull secrets out of a stolen one. A PIN locks the device, and guessing it is capped. A Ledger resets itself after three wrong PINs ([Ledger](https://www.ledger.com/academy/topics/ledgersolutions/ledger-pin-code-what-you-need-to-know)); a Trezor doubles the waiting time after every wrong attempt and wipes itself after 16 ([Trezor](https://trezor.io/learn/basics/what-is-a-hardware-wallet)). A wiped device costs you nothing if you still have the recovery phrase. ## How Is a Hardware Wallet Backed Up? On most devices the backup is made during setup: the device shows the words on its own screen and asks you to confirm them, and Ledger and Trezor [never show them again](/view-seed-phrase/). Write them on paper or stamp them in metal, and keep them somewhere other than the device; [how to store a seed phrase](/store-a-seed-phrase/) compares the options. Never make a digital copy: Ledger’s advice is not to photograph the phrase, save it in a password manager or store it anywhere on a computer or phone ([Ledger](https://www.ledger.com/academy/series/rookie-to-pro/lesson-6-the-final-play-your-first-safe-steps-on-ledger)), because a digital copy puts the words back on the kind of device the hardware wallet keeps them away from. A single copy can be lost to fire or water, so Trezor suggests making several and storing them in separate secure places ([Trezor](https://trezor.io/blog/security/best-practices-for-securing-your-wallet-backup)). Every one of them is a complete copy of the wallet: whoever reads the words can empty it without the device. | Format | Used by | What to know | | --------------------- | ------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------ | | BIP39, 24 words | Ledger, Keystone, COLDCARD | Restores in almost any wallet | | BIP39, 12 or 24 words | Blockstream Jade; Trezor as an option; BitBox02 if you write the words down | The same standard; 12 words give 128 bits, enough in practice | | SLIP-39, 20 words | Trezor Safe 5 and Safe 7, and the Safe 3 since June 2024, by default | Can be split into shares; restores only where SLIP-39 is supported | | Maker-specific | BitBox02 microSD card (its default), Tangem backup cards, Passport Prime Keycards, Ledger Recover | Convenient, but tied to the maker’s devices or service | Each maker documents its own defaults: [Ledger](https://www.ledger.com/academy/topics/ledgersolutions/what-is-ledger-recovery-key), [Trezor](https://trezor.io/learn/security-privacy/personal-security-standards/understanding-trezor-wallet-backups-12-20-or-24-words), [Keystone](https://guide.keyst.one/docs/get-started), [COLDCARD](https://coldcard.com/q), [BitBox](https://support.bitbox.swiss/en%5FUS/bitbox02/advanced-backup-options-bitbox02) and [Blockstream](https://help.blockstream.com/blockstream-jade/faq). Two additions come up often: - **A passphrase.** Most devices accept an optional [BIP39 passphrase](/bip39-passphrase/), the so-called 25th word, which turns the same words into a different wallet. It protects you if someone finds the words, but it is a second secret you have to back up. - **Shares and services.** Trezor can split a SLIP-39 backup into as many as 16 shares and let you choose how many of them restore the wallet ([Trezor](https://trezor.io/learn/security-privacy/personal-security-standards/understanding-trezor-wallet-backups-12-20-or-24-words)); [SLIP-39 vs BIP39](/slip39-vs-bip39/) covers the trade-offs. Ledger sells Ledger Recover, an optional subscription based on your ID: the device encrypts the phrase’s entropy and splits it into three fragments held by Coincover, Ledger and EscrowTech, and two of them plus identity checks restore your keys to a Ledger ([Ledger](https://shop.ledger.com/pages/ledger-recover)). To restore, choose the restore option on a new device of the same brand, or on any wallet that reads the same format, and enter the words on the device; [how to restore a wallet from a seed phrase](/restore-wallet-from-seed-phrase/) has the steps for Ledger, Trezor and others. ## What Does It Protect You From, and What Can’t It Stop? It protects the keys from the computer. Everything else is still up to you, and BitBox’s list of what a hardware wallet cannot prevent sums it up: someone obtaining your recovery words, you typing the words into a computer, phone, website or fake app, you approving an address or amount without checking it, an attacker with both the device and its PIN, and losing the device along with every backup ([BitBox](https://support.bitbox.swiss/en%5FUS/security/can-a-hardware-wallet-be-hacked)). The common cases: - **Phishing for the phrase.** Thieves rarely attack the device; they ask for the words through fake support chats, emails, letters and apps. Trezor will never ask you to enter your wallet backup digitally ([Trezor](https://trezor.io/learn/basics/what-is-a-hardware-wallet)), and neither will any other maker; [seed phrase scams](/seed-phrase-scams/) shows how these requests look. - **Approving the wrong thing.** Malware can swap the address on your computer screen, and a malicious site can ask you to sign a token approval that hands over your coins. The device signs whatever you confirm, so read its screen, not the computer’s. - **A tampered device.** In October 2026 Ledger reported that a criminal group had bought genuine Ledger devices, fitted hidden components that captured the recovery phrase during setup and put the devices back on sale through resellers in Southeast Asia; Ledger found no flaw in its chip, operating system or servers ([Ledger](https://www.ledger.com/blog-response-hardware-implant-attack)). Its Genuine Check confirms that the secure element is real, but Ledger notes the check cannot detect such implants while the original chip is intact ([Ledger](https://www.ledger.com/academy/topics/ledgersolutions/best-practices-to-securely-buy-ledger-signer)). - **A flawed random number generator.** In July 2026 Coinkite disclosed that a firmware bug had weakened COLDCARD seed generation since March 2021; attackers regenerated the affected keys offline and stole funds ([Coinkite](https://blog.coinkite.com/coldcard-mk3-seed-generation-warning/)). Fixed firmware protects new seeds but cannot repair old ones, so Coinkite tells owners of affected seeds to move their funds to a new one ([COLDCARD](https://coldcard.com/security/status)). - **Force.** Someone who threatens you can make you unlock the device. A passphrase wallet, or a duress PIN that opens a decoy wallet, as on a COLDCARD ([COLDCARD](https://coldcard.com/q)), keeps the main funds out of sight. If your words may have been seen, don’t wait for a theft: create a new phrase on the device and move the funds to it. ## Hardware Wallet or Phone Wallet? | | Hardware wallet | Phone or desktop wallet | | ------------------------------------ | --------------------------------------- | -------------------------------- | | Where the keys live | On the device | On the phone or computer | | If the computer or phone has malware | The keys stay on the device | The keys can be copied | | Where you check a payment | On the device’s own screen | On the screen malware can change | | Cost | The price of the device | Usually free | | Backup | A recovery phrase or the maker’s backup | A recovery phrase | Both are self-custody: unlike an exchange account, nobody else holds the keys. A hardware wallet is the most common kind of cold wallet, one whose keys are generated and kept offline, and Trezor’s rule of thumb is to get one once a hack of your exchange account or hot wallet would seriously hurt you ([Trezor](https://trezor.io/learn/basics/what-is-a-hardware-wallet)). Thefts are not rare: Chainalysis counted more than $3.4 billion in crypto stolen in 2025 up to early December, including $1.5 billion taken from the Bybit exchange in a single hack and $713 million in about 158,000 thefts from personal wallets ([Chainalysis](https://www.chainalysis.com/blog/crypto-hacking-stolen-funds-2026/)). Many people keep a small spending balance in a phone wallet and their savings on a hardware wallet; [hot vs cold wallets](/difference-hot-wallet-and-cold-wallet/) compares the two in detail. ## How to Set Up a Hardware Wallet Safely 1. **Buy it new, from the maker or an authorized reseller.** Trezor publishes its [authorized resellers](https://trezor.io/resellers), and Ledger recommends Ledger.com or its listed resellers and warns about unlisted sellers on marketplaces ([Ledger](https://www.ledger.com/academy/topics/ledgersolutions/best-practices-to-securely-buy-ledger-signer)). Skip second-hand devices. 2. **Check the package.** Trezor seals both the packaging and the device ([Trezor](https://trezor.io/trezor-safe-5)), and COLDCARD ships in a tamper-evident bag ([COLDCARD](https://coldcard.com/mk5)). If anything looks opened, don’t set it up; contact the maker. 3. **Install the official app** from the maker’s website or the official app store, and run the authenticity check it offers, such as Ledger’s Genuine Check or the automatic check in the BitBoxApp. Install any firmware update before you create the phrase, as COLDCARD now requires ([COLDCARD](https://coldcard.com/mk5)): an update changes how new seeds are made, not a seed that already exists. 4. **Create a new phrase on the device.** Ledger says a genuine device never comes with a recovery phrase or PIN already set ([Ledger](https://www.ledger.com/academy/topics/ledgersolutions/best-practices-to-securely-buy-ledger-signer)), and the same holds for every maker: if the box holds a card with words on it, whoever prepared it kept a copy. 5. **Write the words down and verify them.** Most devices can check your copy against the seed they hold, as Trezor’s [Check backup](https://trezor.io/guides/backups-recovery/general-standards/check-backup-on-trezor-safe-5) does. 6. **Test with a small amount.** Show a receiving address on the device’s screen, send a little, and move the rest once it arrives. 7. **Keep the firmware updated** through the official app, with your backup at hand. ## What Happens if You Lose the Device or It Breaks? Nothing, as long as you have the backup. Get a new device of the same brand, or another that reads your backup format, choose to restore and enter the words on the device: the same keys and balances come back, because they never lived only in the old device. A finder still faces the PIN and its attempt limit, but if the device was lost along with your notes, or the words may have been seen, move the funds to a new phrase. Maker-specific backups restore only within their own system: a BitBox microSD backup on a BitBox02, Tangem’s backup cards in the Tangem app, Ledger Recover on a Ledger. ## Which Hardware Wallet Should You Choose? Five questions narrow it down: - **Which coins?** Bitcoin-only devices such as COLDCARD, and the Bitcoin-only editions of Trezor and BitBox, leave out the code for other coins; Ledger, Trezor, Keystone and Tangem cover Ethereum, Solana and thousands of tokens. - **How big a screen?** A larger screen makes long addresses and contract approvals easier to read. - **Open firmware, a certified chip, or both?** See the trade-off above. - **Which connection?** A cable, Bluetooth, or an air gap with QR codes and microSD. - **Which backup?** A BIP39 phrase restores almost anywhere; shares and maker-specific backups give up some of that for other strengths. The [hardware wallet comparison](/hardware-wallet-comparison/) puts the current models side by side, with specs from each maker’s own pages. The list of [BIP39 wallets](/bip39-wallets/) shows which apps and devices accept which phrases, and the [Wallets topic](/topics/wallets/) gathers the related guides. ## Frequently Asked Questions ### Can a hardware wallet be hacked? Stealing the keys remotely from a device used correctly is exactly what it is built to prevent, and Trezor notes that compromising one typically takes physical access to it ([Trezor](https://trezor.io/learn/basics/what-is-a-hardware-wallet)). Real losses have come from leaked recovery phrases, malicious transactions that owners approved, tampered devices and, rarely, firmware bugs such as COLDCARD’s in 2026. ### Is a hardware wallet the same as a cold wallet? Not quite. A cold wallet is any wallet whose keys are generated and kept offline, and a hardware wallet is the most common kind. A paper wallet is cold as well, but spending from it means importing its key into software. ### Can I use a hardware wallet with MetaMask or other apps? Yes. Ledger lists compatibility with more than 50 wallets ([Ledger](https://shop.ledger.com/pages/hardware-wallets-comparison)), and Trezor says the Safe 7 works with Rabby, MetaMask and Backpack, among others ([Trezor](https://trezor.io/trezor-safe-7)). The app is only the interface: the keys stay on the device, which still shows and signs each transaction. The PDF archive has step-by-step guides to pairing a QR-code signer such as the Keystone 3 Pro with [BlueWallet](/list-keys/private-key-list-bitcoin-03-25-2025/) for Bitcoin, [Solflare](/list-phrase/bip39-seed-phrase-list-03-26-2025/) for Solana, [VESPR](/list-phrase/03-29-2025-and-seed-phrases/) for Cardano, [Fewcha](/list-phrase/bip39-seed-phrase-list-03-28-2025/) for Aptos and Sui and [Helium Wallet](/list-phrase/bip39-seed-phrase-list-03-25-2025/), and to using one with [MetaMask](/list-keys/private-key-list-ethereum-03-25-2025/) on Ethereum. ### Do I need Ledger Recover? No. It is an optional paid subscription, and your 24 words restore the wallet without it. Ledger also points out that Recover restores your keys to a Ledger device but cannot give you back the recovery phrase itself ([Ledger](https://shop.ledger.com/pages/ledger-recover)). [ Back to Blog ](/blog/)