Source
r/ledgerwallet•
php_questions

Leger Device security vs trezor

What does the physical security of a ledger vs a trezor look like? I know that the ledger has a secure element and that the trezor has not, but lets assume I use a passphrase on both devices and lets assume that someone steals my hardware wallet as attack scenario.

My 24 seed phrase + passphrase seems to only be protected by the PIN of the ledger devices, wouldn't an attacker be able to just bruteforce this PIN and get to both my seed phrase and passphrase at the same time? How long would it take someone to bruteforce a 4 digit pin, 6 digit pin or 8 digit pin? I would image it is not very long.

Now contrast this with the trezor, the trezor does not store your passphrase on the device, you need to enter it via the software that uses your trezor. That means that when someone steals the trezor device, it should not be able to get to my 25th passphrase.

So isn't the trezor device more secure in this attack scenario?

Posted Aug 3, 2020, 8:46 AM UTC

117
btchipLedger Innovation Lead & Co-Founder•

You can do exactly the same with Ledger if you want - just use a temporary passphrase. I wouldn't suggest you use passphrases unless you're absolutely sure about what you're doing though, because it's an easy way to lose assets if you forget about it - that's a major difference with Trezor, where they're absolutely mandatory if you want to have some kind of (inconvenient and partly broken) protection against physical attackers.

3
php_questionsOP•

But on the ledger you have to type in your passphrase via the device every time, right? That makes it much more inconvinient, and people either won't use it or they will pick suprt short passphrases which both harm security.

If you contrast this with the trezor, it lets you type in your passphrase via software on your computer. Yes, your computer may have malware on it and you may give away your passphrase this way, but without the seed phrase the passphrase is useless.

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So to recap: If someone steals your ledger, they can bruteforce the pin and get to your money in a day or a couple of days (Is that fair?). On a trezor, someone will have to steal your device AND install malware on your PC to get to your passphrase.

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Doesn't that mean that indeed, a trezor is more secure against physical attacks?

2
btchipLedger Innovation Lead & Co-Founder•

You can also type it on a computer if you want, even though I would recommend it even less than having a passphrase (see https://github.com/LedgerHQ/blue-loader-python/blob/master/ledgerblue/hostOnboard.py)

Also there's no simple way to bruteforce the PIN on a smartcard chip - it's not a MCU you can break in 2 minutes.

2
saggy777•

With passphrase, absolutely yes

1
btchipLedger Innovation Lead & Co-Founder•

With a passphrase an attacker could flash an arbitrary firmware that make you reveal it. The attack is slightly more complex to pull off - you'd either have to swap the device for another one in the process, or force the firmware into the current device without damaging the case (which is realistic through electromagnetic fault injection, IMHO)

1
kun9999•

Ledger device will automatically reset after enter 3 wrong pin and no proven method to brute force it even if hacker have physical access to the ledger device Anyway do look into this article too Kraken Identifies Critical Flaw in Trezor Hardware Wallets https://blog.kraken.com/post/3662/kraken-identifies-critical-flaw-in-trezor-hardware-wallets/ and other security flaw found https://donjon.ledger.com/

3
php_questionsOP•

I didn't know it resets after 3 attempts, but still, couldn't someone just bypass the software that is requiring the PIN and just go straight to the data store and bruteforce that with the PIN?

1
kun9999•

Until today there's no proven way to bypass the 3 wrong pin reset but if you wish to further secure your crypto you can always use the 25th word passphrase (max 100 char) method.

2
php_questionsOP•

i dont really understand that part. Compare it with disk encryption. You might have a bootloader that will wipe your disk when you enter the wrong ping 3 times in a row, but you can't stop someone from just copying the encrypted data somewhere else and attempting to decrypt that data manually while bypassing the wipe after 3 incorrect attempts.

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I assume that this would also be possible on a ledger, instead of using the software (which will wipe the device after X failed attempts) someone could manually attempt to decrypt it and bruteforce the pin this way

0
kun9999•

Ledger have something call secure element which prevent this kind of attack, similarly to those smart chip in credit card if I am not wrong.

Perhaps this article will help https://www.ledger.com/academy/security/the-secure-element-whistanding-security-attacks

3
VariousJackfruit•

That's the entire point of the secure element: the data contained can't easily (nothing is "impossible") be copied out.

1
saggy777•

To answer your question, yes Ledger is less secured when you choose to associate paraphrase with PIN because that too is stored in the device. However you can choose to not associate with PIN but in that scenario it is less convenient than trezor because you need to type it on the device everytime you want to use the device.

1