Yes I probably am being paranoid.  For what its worth I've just thrown around 0.02 BTC onto the Brain Wallet address which I'll leave there and see if it gets hacked in the months/years ahead.

You're right, I do carry my hardware wallet keys with me currently in the form of encrypted USB's - I don't leave them on any computer or any cloud service. I guess if things ever became extreme, I would just stop travelling with the hardware wallets, only the USB's which everyone carries and are not suspicious as such.

I don't have enough faith in my memory to remember a random seed word, especially when dealing with large sums, multiple devices etc.

The consensus is definitely not to use a brain wallet. How do people propose to cross borders in a distant future if there are crack downs eg. you your hardware devices will be confiscated at borders?

I'm basically looking for a way to store and travel with Bitcoin in worst case scenario where govt's are actively attacking Bitcoin or at the very least trying to track/record what you hold. If that doesn't happen, then I'll continue to use my hardware devices and never have the need, but like to plan for such eventualities and even now beginning to be concerned travelling with them as at some point in time in some random border crossing, an official who actually knows what the devices are may pull you up.

Another method that comes to mind is to use the different hardware devices stored in different countries to bounce the Bitcoin back and forth if required and never actually technically travel with it. But this is still problematic.

Happy if anyone has some resources on operating procedure to do with the above they can link me to read up on.

Thanks for the comments and reference links LoyceV.

So it is not a BIP39 wallet I've created, just a brain wallet. I will have a good long think about whether to continue with my theory after I've had a chance to re-read all the references provided here by yourself and others thoroughly again.

When you say I would need to use similar brain wallet software to recover, can you name some examples of such? Clearly I haven't used that type of software before, so unless I can get my head around it, it would seem too unsafe to risk using my current brain wallet and will need to change plans. To confirm, I believe you're saying the private key generated from the existing wallet can't just be used in most wallet recovery services even with the key itself (ie. not the seed phrase)?

Thanks for the reply.

How would I know if there was a checksum in my phrase? I've been able to generate both public and private keys, able to verify the public address on the blockchain - does this mean it would be ok?

So if I understand correctly, you're saying I could just regenerate private keys then scan QR codes into wallet. The phrase I have used generates private keys in bitaddress.org but when doing it in iancoleman, it says obviously words not in wordlist. Does this mean the private keys spit out by bitaddress might not work?

Thanks for the reply. The main reason being I don't have enough faith in my memory for a set of random 12 words. The same reason I need to record the seed phrases for my Ledger devices.

This brain wallet seed phrase however - as an emergency temporary solution - does not have the seed phrase recorded anywhere what so ever, even on the encrypted USB's. This is why I feel the need to generate a phrase I will remember, both from repetition now, but also as even if I have a word or two around the wrong way in 5yrs, I'll still be able to get it again through process of elimination (worst case scenario, I am comfortable with my memory for this phrase.)

Thanks for the links. Yes I also used the Github link you provided at the time (offline) to verify the seed phrase just to ensure all was correct and not relying solely on bitaddress.org - but you're saying as I didn't use words that exist in the BIP39 list, I won't be able to restore the wallet anywhere?

I used bitaddress.org offline to generate the private key using the chosen 12 word phrase. Then took that private key generated and went to wallet details on same site (still offline) to generate the Public Key to be able to send to.

I made a sentence which I can remember. I don't have confidence over long term (talking years) to be able to remember a random selection of 12 words. Whilst I'm aware a human created phrase is less secure, it is not a phrase that has ever been written anywhere in history (ie. from a book etc) and involves ancestors name and totally unrelated topic, so I can't see how it could ever be hacked? eg. something like "yohan sputz went to romania in 1848 and ate some good cake" - that's not it, but not sure how that could be brute forced or guessed?

Happy to be corrected though!

For me the reason for the mnemonic being a phrase I can remember is basically because it will only be used years from now in an emergency eg. govt. attack at border check point as a random example. So likely would only be worst case scenario, and for a limited time.

My every day security protocol is:
- Multiple Ledger Nano S devices,
- Stored in different physical locations
- Recovery seeds for those on multiple physical pin pad encrypted USB's (different brands and physical locations)

My apologies for the perhaps basic question, but I have searched and cannot seem to find an answer.

Up until now I have only used Ledger Nano S devices to store my Bitcoin and hold my private keys. I keep the recovery seed phrases for these secure.

However for the first time I have now also created a brain wallet. Whilst I do not intend to use it for the moment, I feel it is good practice to already have it in place now with a secure pass phrase that I have committed to memory. In the event of an unforeseen event or emergency in the future, I already have the Public Key to send to and have the ability to re-generate the private keys using the memory committed 12 word passphrase.

My question is, which wallet is the best in an emergency to recover this seed phrase to? It is a unique phrase that I created with the BIP39 tool (offline) and only has 12 words, though they are unique and memorable to me. My concern is the words don’t conform to the English BIP39 standard words and as such can’t be restored into wallets like Electrum or my Ledger devices.

Is anyone able to advise wallet services where one can restore a truly unique 12 word passphrase that wasn’t generated by a wallet service?

Or am I going about this the wrong way and in the event of recovery, simply generate the Private keys using the BIP39 tool and then use the private keys themselves in a wallet to restore?

Again, sorry for the basic question!