That’s definitely bad way because it’s not going to be that random. Before then you need to understand that you cannot just choose words like that, for wallets like Trezor the seed phrase have to be in the BIP-39 word list before they consider valid. Any random word won’t even give you a valid checksum. The last 8 bits are your checksum so for the last word 8 out of the 2048 will be what will produce a valid checksum, now check the probability of that happening it’s like 1 in 256. If it’s difficult like this then compare it to a non bip39 wordlist of 2048.

Aside that, randomly picking words doesn’t create enough randomness needed. It’s a bad choice

I really didn’t know this. I thought we could just choose random words. Thank you very much.

Lol I have thought and tried this and despite how random since I picked most words during travels
While I noticed some bias that's why I realised why many just use random generators.
Humans tend to have bias despite how deep we try to numb them
Security isn't based on how hard a word is but the level of entropy.

Trezor is using BIP39 seed phrase, getting random 12 to 24 word as seed phrase will be invalid on Trezor. One of the ways that it can be valid is BIP39 import on Electrum. So if the OP trying to do that on Trezor, it will not even work.

@standardnepo, you know already that it may not create enough entropy and such wallet will likely be very vulnerable to hack.

You are mixing things and I think you don't know how bip39 work. By the way, humans are very bad at creating a good entropy by mere selection, using a dice is better.

First of all, you can't select a word out of bip39 word list to create a valid bip39 mnemonic, it is not going to work if you select words from songs, movies, anywhere that is not bip39.

Let's assumed you selected random words from bip39 word list, you can't generate the complete seed words to create a wallet because the last word isn't a complete entropy. It contains both entropy and checksum, you have to hash the entropy to get the checksum, without the checksum it will be invalid.

The 12 words is 128 bits has 4 bits checksum, the 4 bits is added to the entropy to give 132 bits, these bits are split into 12 groups of 11 bits, converted to decimal and then converted into seed words from the wordlist. The 24 words which is 256 bits has 8 bits checksum, it's added to the entropy to give 264 bits, these bits is split into 24 groups of 11 bits to match the wordlist.


Trezor is not ledger, if you buy your Trezor directly from the Trezor company and not a distributor, you have nothing to worry. There is also not a confirmed report that hardware wallet bought directly from ledger has a problem. The affected ones are mostly from a particular distributor.

Words in your wallet seed phrase must be in BIP word lists, and there are different BIPs.
You can not create a list of 12 or 24 words which have words that are not in any BIPs and think you have a completed and usable wallet seed phrase.

How many Bitcoin seed phrases are only one repeated word?

Additionally, there are conditions for a combination of words in a BIP word list to make a valid wallet mnemonic seed phrase.

I'd imagine that the "hack" on ledger was based on the fact that the device was physically tampered with (with eSim, and screen captured). Therefore, even if you create your own 24-word passphrase, and *if* the device is still physically tampered with - this won't help.

I wouldn't recommend making your own seed phrase that way. Even if the words come from random sources, you still need to select them in a way that provides enough entropy, and a valid wallet seed also involves a specific checksum. It's safer to let your Trezor generate the seed phrase, since it's designed for that purpose. If you're worried about security, focus on keeping your seed offline and making sure nobody else can access it. There's no need to make things more complicated if your current setup is secure.

No wallet supports a system where you can create your own wallet security seed phase and use it. BIP39 certainly doesn't, but if that were possible, everyone would create their own wallet of choice. If your chosen words are in the BIP39 list, then the wallet might support them, but if your words are not in the BIP39 vocabulary list, it will never support them and no wallet will ever approve you.