Storing Bitcoin about 20 years and is offline paper wallet (Bitaddress) secure?

[coinomari]

Hello,

I see Bitcoin as an alternative finance system and would like to store Bitcoin over a 20 year period. Therefore, I don’t really need all that media drama. I just want to "set and forget” about it. Having a moderate amount of Bitcoin (about 0.5) on Coinbase causes some distress - not my keys, not my Bitcoin. All that media drama and blockchain influencer blah blah is definitely too much drama for me and causes me headaches.

Since I have a long-term view, I don’t know about hardware wallets whether they are compatible with my PC in 2040 or so. And then I would be paranoid enough to buy 10 hardware wallets in my case. Paper wallets will always exist, but I don’t know about their safety, even with just 0.5 Bitcoin distributed over 50x paper wallets and 50 feet underground (what I would like to do.)



Therefore, I have currently some tools: a 10-year old laptop without hard drive, Ubuntu DVD, 10 new Sandisk USB flash drives (saving as PDF, no paper priting) and the offline version of www.bitaddress.org.

My starting point for all these thoughts is this tutorial:
https://99bitcoins.com/bitcoin-wallet/paper/

My plan is as follows:

1. Use the old laptop only for generating Bitcoin paper wallets (no hard drive, just Ubuntu DVD) with the the offline version of www.bitaddress.org

Generating paper wallets with just private keys is all right? Or is the “BIP38 Passphrase” feature a must do from bitaddress.org for maximum security?

2. Save 50x wallet addresses as 50x PDF files and transfer it on all 10x USB flash drives, use water/fire-proof packaging and bury them 50 feet underground. They went straight from offline PC to 50 feet underground.

3. Take a picture of each Bitcoin address / QR code (only the QR/address, nothing else) with an old camera (SD card) from laptop monitor and use OCR to have them in “copy & paste” format for online PC. I sure have to know where I have to send them from Coinbase.

4. Transfer my 0.5 Bitcoin from Coinbase to these 50 wallet addresses (so like 0,01 Bitcoin to each wallet)

5. Forget about it and move on with life


Addition questions:

   1.   Are paper wallets in general safe if stored correctly? Is BIP38 really necessary if I store my Private Keys 50 feet underground? Otherwise I have to write down 50 BIP38 phrases for 50x offline generated wallets and I fear I will look myself out when I want to retire

   2.   What is currently the most secure and “only the paranoid survive” way to generate a wallet address and store Bitcoin nuclear-war proof? It shouldn’t be rocket science, although I feel like it has to be somehow? If I have to spend $1,000 for more tools, that's all right for some peace of mind for a 20 year period.


   3.   Is www.bitaddress.org in general the way to go for offline wallet generation and free of errors? I’ve heard that JavaScript could cause some problems with generating the wallet offline? Their current Github version is from Dec 24, 2016, which is somewhat odd. But maybe never change a running system, huh? Has anyone ever had a problem with them if generated offline with Ubuntu DVD?


4. 10x USB flash drives are redundant enough for a 20 year period?

I'm concerned about Bitaddress because someone also said in another Reddit thread:
"Please don't use any javascript address generator for anything that matters. The common libraries they have used have had a long and worrying series of mathematical flaws that cause them to occasionally generate addresses that do not match the private keys, and were completely without the sorts of test that would have detected these mistakes. Even if the errors are all fixed now, it's very easy for a webpage generator to be using an old version without anyone really noticing."

https://np.reddit.com/r/Bitcoin/comments/6ss91w/seriously_how_are_you_all_generating_your_private/dlf4uhr/


5. In the future, quantum computers will probably not be able to “crack” offline generated wallet addresses or wallets in general, regardless of whether I use BIP38 or not? I just want some peace of mind, thanks again.





I think you see my problem/challenge: storing Bitcoin over a 20 year period, store it as securely as possible and forget about it, and move on with life. If anyone knows better tools/ways to accomplish this, I would be forever thankful.

If I do everything correctly the first time, I don’t have to worry constantly about what this or that media outlet / expert says.

Thank you very much everyone for your help/suggestions/criticism. And sorry in advance for any stupid question, but this is at least to me at lot of money. And I have the feeling that paper wallets keeps Bitcoin safe from others as well as myself (not exchanging them for "fairy tale fiat money".)

[franky1]

paper can get wet/burn, decompose, ink fades

try drilling/ etching into metal

using seed phrase. you can drill out holes for each word

just the first 4 letters can tell you the word
so
      A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z
1    x
2        x
3    x
4                                                       x
=ABANdon
do for all 12-24 words

or its words numeric position in the known word library
     0  1  2  3  4  5  6  7  8  9
1   x
2   x    
3   x
4       x                                  
0001=abandon
do for all 12-24 words

metal lasts longer is fire proof and damp proof

...
the good thing about keys is that your are not limited to one storage. one format of said storage. so dont feel limited to one type

[Eternad]

I bitaddress.org before when I was newbie here to print my own paper wallet. I laminated it to make it safe from physical destruction. Until my wallet balance is still intact so I can vouch about the reliability of Bitaddress as source of paper wallet address.

But I really suggest to use hardware wallet instead of paper wallet if you are holding for that long time. I can’t assure if you can protect a paper for a long time compared to hardware wallet which you can store and use freely whenever you want. You should invest on Hardware wallet if you plan for saving in long term.

[Timelord2067]

You might want to investigate using wax or some other sealant to coat the SD cards/USB thumb drives etc to prevent any moisture getting inside.

Additionally, people use PVC pipes (sealed up at each end) to store items in which they bury (vertically to lower the amount of its "foot print" by metal detectors) additionally, items such as mosquito coils (or even cheap incense sticks) are added to the pipe - lit and smouldering which uses up all available oxygen that could cause rust to items inside the tube.

[hosseinimr93]

Since I have a long-term view, I don’t know about hardware wallets whether they are compatible with my PC in 2040 or so. And then I would be paranoid enough to buy 10 hardware wallets in my case.

The hardware wallet should give you a seed phrase (a series of 12/24 words) that can be used for recovering your wallet at any time. All your private keys can be derived from the seed phrase and as long as you have the seed phrase, there's nothing to worry about. As far as I know, most of hardware wallets should give you a BIP39 seed phrase.

Paper wallets will always exist, but I don’t know about their safety, even with just 0.5 Bitcoin distributed over 50x paper wallets and 50 feet underground (what I would like to do.)

If you want to have 50 bitcoin addresses, go for a HD wallet with a seed phrase. In this case, instead of keeping 50 different private keys, all you need to keep is a seed phrase. That would be much easier.
Also note that with using 50 addresses for holding the fund instead of using a single address, you will have to pay more fee.
If you generate the private key/seed phrase using a safe tool on an airgapped device, your fund would be safe. I recommend you to use electrum.

[BlackBoss_]

Metal steels are better than paper to store your seeds and they are water, fire, acid, stress proof better than paper.

Crypto Security - Additional Protection For Your Seed/Private Keys.
Securing Your Seed Phrase with Washers
[LIST] Bitcoin Seed Backup Tools
Metal Bitcoin Seed Storage Reviews

[coinomari]

Thanks for the replies so far. I don't want to store the private keys exactly on paper but on 10x Sandisk USB flash drives.

Here is my short plan:

1. Offline laptop + Ubuntu DVD + Offline version Bitaddress.org on USB flash drive
2. Generate 50x offline wallets without BIP38 to make things not even more complicated
3. Save 50x offline wallets from Firefox as 50x PDF files on 10x USB flash drives for maximum redundancy and security
4. Take a picture of the public address / QR code with an old camera (SD card)
5. Bury the 10x USB flash drives with 50x offline wallet private keys like 50 feet underground
6. Transfer all 0.5 Bitcoin to these 50x offline wallets
7. Set and forget about it and bury them out in like 20 years or so to keep them safe from others as well as myself



I'm concerned about Bitaddress.org because someone also said in another Reddit thread:

"Please don't use any javascript address generator for anything that matters. The common libraries they have used have had a long and worrying series of mathematical flaws that cause them to occasionally generate addresses that do not match the private keys, and were completely without the sorts of test that would have detected these mistakes. Even if the errors are all fixed now, it's very easy for a webpage generator to be using an old version without anyone really noticing."

https://np.reddit.com/r/Bitcoin/comments/6ss91w/seriously_how_are_you_all_generating_your_private/dlf4uhr/

[m2017]

OP approached the solution of the btc storage method with maximum creativity. Quite an interesting description.

In this scheme, I have doubts that all data will be stored on digital media: PDF files on flash drives and on an SD card. In 20 years, these devices can fail, especially since it don't have a backup power source and flash drives with an SD card will not be connected to a PC or other devices. In short, without access to electricity, this data simply will not be stored for so long (if this is not a myth). Also, the shelf life of these devices can be corny less than a period of 20 years.

Therefore, I think that here it is necessary to carefully consider the method of storage.

Just in case, it would not hurt to add the good old way of storing information on a piece of metal.

[hosseinimr93]

2. Generate 50x offline wallets without BIP38 to make things not even more complicated

As I said in my previous posts, it would be better to generate a HD wallet with a seed phrase.
The seed phrase is a series of words that can generate numourous private keys. In this way, you don't need to keep 50 private keys. All you need is your seed phrase.

6. Transfer all 0.5 Bitcoin to these 50x offline wallets

Why are going to do that? To increase you security?
A single address is enough, unless you want to have multiple addresses due to privacy reasons.
Take note that to do so, you will have to spend some fee for splitting the fund. You will also have to pay more transaction fee when spending the 0.5 BTC.

I'm concerned about Bitaddress.org because someone also said in another Reddit thread:

That's right. I wouldn't use Bitaddress for generating wallet.
Use electrum. It's open-source and compeltety secure, if it's used properly.
In electrum, you can generate a HD wallet and you will have a seed phrase which can be used for deriving all the private keys and address. You will also have the opion to export individual private keys.

[Erumo]

Use any way you want to store your Bitcoin, just remember to make it easy to access. Dont store your paper wallet in a metal box, that you will put into safe, which your will bury, pour concrete and plat a tree above it. Just laminate your piece of paper and that is it. The more sophisticated you are in storing, the worse and complicated it will be in the end.

[franky1]

i know your thinking of he air gapped pc and usb wallet generation stuff.. but also think abut that USB longevity with a pile of wet soil on it for 20 years. rusting the metal connectors and seeping dampness inside the gaps to get to the circuitry inside

think about water proofing(vacuum seal bags) and lockboxing it, to give it a metal box coffin to reduce the damage 20 years of being buried can do.

[mendace]

It sounds like you are taking a very cautious and thorough approach to storing your Bitcoin for the long-term. Using a hardware wallet or paper wallets can be a good option for long-term storage, but it's important to understand the pros and cons of each method.

• Generating paper wallets with just private keys is generally considered safe, but using the BIP38 Passphrase feature can add an extra layer of security. This feature allows you to encrypt your private key with a password, making it more difficult for someone to access your funds if your paper wallet is lost or stolen.
• Storing paper wallets correctly, such as in a fireproof and waterproof container and burying them underground, can make them very secure. However, it is important to remember that if you lose access to your paper wallet, you will also lose access to your funds.
• Using the offline version of www.bitaddress.org is a widely used and generally considered safe method for generating paper wallets offline. However, as you mentioned, it's important to ensure that you are using the most recent version of the software.
• Using multiple USB flash drives for storage can provide added redundancy and security, but it's important to ensure that they are stored in separate locations to further protect against loss or damage.
• Quantum computers are a developing technology and it is uncertain how they will affect the security of current encryption methods in the future. However, using a long and complex BIP38 passphrase can help protect against potential quantum computing attacks.

Overall, there is no single "perfect" method for storing Bitcoin, and it's important to weigh the pros and cons of different options and choose the one that best fits your needs. It's also a good idea to keep your storage methods updated and to regularly check on the status of your funds.

[coupable]

6. Transfer all 0.5 Bitcoin to these 50x offline wallets

Why are going to do that? To increase you security?
A single address is enough, unless you want to have multiple addresses due to privacy reasons.
Take note that to do so, you will have to spend some fee for splitting the fund. You will also have to pay more transaction fee when spending the 0.5 BTC.

I agree with you on all your opinions on the topic, and I wonder, like you, why op seeks to follow the most complicated path while he can generate many addresses using one seed phrase.
Regarding the point in the quote, I have a technical question that may seem silly to some, but I really don't know it: If the entire amount (let's say 1 btc) is stored in one address, then the owner wants to send part of it (let's say 0,5 btc) to another address (let's assume that he does not own the address to which he will send bitcoins) without specifying Change address to receive the rest of the amount, what should happen in this case? Will there be a defect in the transaction and therefore the user will not be able to broadcast it? Or will the rest of the amount be returned to the same address from which it was sent?

[coinomari]

Thanks again for the many helpful replies that got me thinking.

If I'm going to go the hardware wallet path, Electrum + Ledger Nano is the way to go? It's like 99% of everyone here does it?

And I can also use offline laptop + Ubuntu DVD for the setup up for additional security? As I've said, I'm only interesting in creating some offline wallets, then sending my Bitcoin from Coinbase to the wallets and then keeping the Ledger away for many years.

The only thing I have to worry about is the 24-word seed phrase and keeping it safe? Maybe I will use different and rarely-used languages for more safety regarding the words.

If the Ledger USB devices doesn't work anymore after 2 years or so, I don't have to worry about anything as long as I have my 24-word seed phrase? I can just buy a new one and use my old 24-word seed phrase and everything is like before and all wallets are available just through the seed phrase?

Thanks again for your help.

[LoyceMobile]

I like how thorough you are, but I think you're over complicating things and putting too much long term trust in flash cards.

LoyceV: read this from desktop!

To start:
Don't make up your own seed words, it won't make it safer but increases the risk of messing up.
Whatever you choose, test it with a small amount and see if you can recover your coins before funding more.

[hosseinimr93]

If the entire amount (let's say 1 btc) is stored in one address, then the owner wants to send part of it (let's say 0,5 btc) to another address (let's assume that he does not own the address to which he will send bitcoins) without specifying Change address to receive the rest of the amount, what should happen in this case?

Generally, if you make a raw transaction and spend a partial amount without specifying an extra output as the change, all the remaining balance goes to miners.
Assuming you use a UTXO which is worth 1 BTC and send 0.5 BTC without specifying the change address, 0.5 BTC would go to the recipient and 0.5 BTC would go to miners as the transaction fee.
Of course, there shouldn't be any problem if you don't make the raw transaction yourself and it's made by your wallet.
For example, if you import a single private key into electrum and make an imported wallet including only one address, the change is sent back to the sending address.

If the Ledger USB devices doesn't work anymore after 2 years or so, I don't have to worry about anything as long as I have my 24-word seed phrase? I can just buy a new one and use my old 24-word seed phrase and everything is like before and all wallets are available just through the seed phrase?

Right. All you will need to recover your wallet is your seed phrase. Your seed phrase can generate all your private keys.

[darkangel11]

You might want to investigate using wax or some other sealant to coat the SD cards/USB thumb drives etc to prevent any moisture getting inside.

Additionally, people use PVC pipes (sealed up at each end) to store items in which they bury (vertically to lower the amount of its "foot print" by metal detectors) additionally, items such as mosquito coils (or even cheap incense sticks) are added to the pipe - lit and smouldering which uses up all available oxygen that could cause rust to items inside the tube.

There's a dozen ways to do it, one of them being lamination. There's many places where you can do it cheap within seconds and to get into the card you just need a knife or a pair of scissors and it's unsealed.

The cheapest way is to use a simple plastic bottle to store your USB drive if water damage is what you're mainly afraid of.

With a few bucks you can buy a metal container like this
Then you can simply drill a hole in the floor or a wall and put it there. It's going to last forever, as long as the house doesn't get bombed or demolished.

[serjent05]

I believe keeping the private key or the seed phrases in the hardware wallet and keeping a tangible backup is a good approach.  We all know that using hardware wallet gives securities but in case of gadget malfunction, we should have a tangible backup such as paperwallet (it is up to you if you will use wood or metal in engraving your seed phrase or private key)  You can also use softwares to encrypt your private keys.  You can also use a multi-signature wallet and split the private key among multiple devices as it increases the security of your created wallet a fail-safe method in case your backup got compromised.  Just make sure that the backup is securely placed in a rustproof, waterproof, and fireproof place.

[Vampobit]

Everyone have contributed with their opinions here and so far, I believe every important thing has been said.

Two points:

1. Don't trust flash memory. It is not good for long-term storage. The most durable is the HDD. However, due to moving parts that exist in HDDs, you shouldn't put pressure on them.
2. If you generate 50 paper wallets, you will need to backup 50 private keys. It is doable, but not the best choice.

Why don't you do the following:

1. Buy an airgapped hardware wallet, like blockstream jade, seedsigner etc.
2. Create a wallet, totally offline.
3. Make 2 backups of the seed phrase.
4. Store the backups in different locations.
5. Generate an address.
6. Save the address on 2-3 places, so you don't need to open the wallet again.
7. Send BTC to this address.
8. Repeat step 7 as many times as you want.

In 20 years:
1. Turn on your device, if it still works. It should have the private keys in it. So you can do whatever you want.
2. If the device doesn't work, you can order a new device from the same company and recover the wallet.
3. If the company doesn't exist anymore, you can enter the seed phrase in any wallet you want and recover the funds.

Bonus point: You can create a watch-only address in your mobile device so you can see daily that everything is ok with your hardware wallet.

[coinomari]

Thanks again for the many responses.

I've heard that Ledger is one of the best hardware wallets out there - on the other hand, I don't know whether they can be trusted after the well-known data leak from 2020?

https://www.bleepingcomputer.com/news/security/physical-addresses-of-270k-ledger-owners-leaked-on-hacker-forum/

If anyone has a good recommendation for a trustworthy hardware wallet that works very well with Electrum (offline) and doesn't require a rocker science degree, thanks a lot in advance.

[LoyceV]

Now that I'm back at my keyboard, some thoughts:
I'm not sure how serious you are about 50 ft deep, but that could make people very curious.
Creating 50 different addresses means you'll have to pay transaction fees 50 times in the future. Depending on fees, that may or may not be a lot (the highest I've paid was about 0.001 BTC in fees back in 2017, and that would be 10% of each wallet.
Don't worry about hardware wallet compatibility, worry about being able to restore the private keys without the wallet. iancoleman.io makes that possible (of course, take precuations and don't just use your regular computer). So if you want to put anything on a flash drive, download that software!
I wouldn't call an unencrypted PDF on a flash drive safer than a printed page. Get a cheap dumb (laser) printer, connect it by cable, and (when dry) the paper will last hundreds of years.
BIP38 is very strong encryption. If you lose the password, you won't be able to crack it. For consideration: you can use both: print the same paper wallet with and without encryption, one as a convenient backup, one burried 50 meter deep. If you forget your password, get a shovel.
If you start digging holes, you may not want to burry all of your wallets at the same place. Remember what happened to +34° 59' 20”, -106° 36' 52”? Dig multiple holes!
If you're really going to trust flash drives for a long time, don't get them all from the same brand. Some may last longer than others.
Coinbase probably charges high withdrawal fees, so you'll have to create a "pay to many" transaction by yourself.
If you worry about quantum computers, the world has bigger things to worry about first. The entire banking system and economy for instance. You'll have time to dig up your coins.
Will you still have access to your digs in 20 years? Any chance they'll build a highway on top?

As a test: create a paper wallet. Encrypt it. Store it. Remember the address.
Turn off your computer, start over. Get your paper wallet. See if you can recover the private key that generates the address. This shouldn't cause any problems, but you should test it to make sure.

[coupable]

If the entire amount (let's say 1 btc) is stored in one address, then the owner wants to send part of it (let's say 0,5 btc) to another address (let's assume that he does not own the address to which he will send bitcoins) without specifying Change address to receive the rest of the amount, what should happen in this case?

Generally, if you make a raw transaction and spend a partial amount without specifying an extra output as the change, all the remaining balance goes to miners.
Assuming you use a UTXO which is worth 1 BTC and send 0.5 BTC without specifying the change address, 0.5 BTC would go to the recipient and 0.5 BTC would go to miners as the transaction fee.
Of course, there shouldn't be any problem if you don't make the raw transaction yourself and it's made by your wallet.
For example, if you import a single private key into electrum and make an imported wallet including only one address, the change is sent back to the sending address.

This seems somewhat terrifying if we consider that this hypothesis is possible if a paper wallet is used with a single address and key. This brings us to the conclusion that using this method of storage is very dangerous without the user having the necessary technical knowledge.
Also, generating 50 addresses in the same way would cost a lot of fees, even if he wanted to send bitcoins to all addresses in one transfer. In this case, he has to receive the entire amount on a wallet that enables him to make multiple transfers. Not to mention the time it will take.

[Leviathan.007]

Regarding storing bitcoin for the long term some people think the most important thing and hardest thing to do is to be able to hold bitcoin even when the price spikes and does sharp movements while I think when we are talking about holding for the long term the important thing is how and where you want to hold your assets, I think where ever you hold the bitcoin you will still need to check and make sure your wallet is safe time by time so holding in underground by writing recovery seed of paper won't be a good solution and amount all the option I would use the please of paper and check the recovery seeds and wallet time by time to make sure my bitcoins safe for long term.

[Synchronice]

I think that it's a pain in the ass to save 50x wallet address, then create 50x pdf, then transfer it into 10x usb, do this, do that, etc.
This is simple and pretty good idea:
1. Buy a Cryptotag Zeus - Click here. Here is the video - How to use cryptotag.
2. Record recovery words and close.
3. It may sound unethical but I think that you can feel safe if you bury it under the grave of your old relative and save there. I think that it can be safe this way and you won't have a need to do tens of wallets with divided bitcoins.

[franky1]

I think that it's a pain in the ass to save 50x wallet address, then create 50x pdf, then transfer it into 10x usb, do this, do that, etc.
This is simple and pretty good idea:
1. Buy a Cryptotag Zeus - Click here. Here is the video - How to use cryptotag.
2. Record recovery words and close.
3. It may sound unethical but I think that you can feel safe if you bury it under the grave of your old relative and save there. I think that it can be safe this way and you won't have a need to do tens of wallets with divided bitcoins.

note about 3:
a. getting local permit to exhume a relative from their grave
b. to get the grave exhumed
c. to then put metal under their coffin
d. re-bury the coffin

and you call that less of a pain in the ass compared to printing some PDF or saving PDF to some USB sticks ?

[Synchronice]

I think that it's a pain in the ass to save 50x wallet address, then create 50x pdf, then transfer it into 10x usb, do this, do that, etc.
This is simple and pretty good idea:
1. Buy a Cryptotag Zeus - Click here. Here is the video - How to use cryptotag.
2. Record recovery words and close.
3. It may sound unethical but I think that you can feel safe if you bury it under the grave of your old relative and save there. I think that it can be safe this way and you won't have a need to do tens of wallets with divided bitcoins.

note about 3:
a. getting local permit to exhume a relative from their grave
b. to get the grave exhumed
c. to then put metal under their coffin
d. re-bury the coffin

and you call that less of a pain in the ass compared to printing some PDF or saving PDF to some USB sticks ?

It depends on what kind of grave your relative has, there are a lot of graves with enclosed areas with ground soil through the stone to limited area. That person can bury it deeply under the soil. Easy right? And I think that's a pretty safe area.

[so98nn]

I think OP's plan is good but as stated by few, paper storage can get way obstructive in the future and in the long run it could be harmful as you may loose the data. I mean even one letter from the print getting lost is losing of your whole bitcoins stored on it. There are many modern ways to do it and way secured than we predict. Hardware wallet can really do this job easily and I do not think we have to overthink about it in the long run. I think we can still go with the flow and modern ways of securing our funds. I mean I am not saying go online with our ledgers. You can always generate an address from the hardware wallet and never plug it until your target is achieved. You can keep funding the address and be secure all the time.

[franky1]

grandma's body 6foot deep with a tombstone marker of where to dig.... is not really a deterrent if the treasure is worth enough(grave robbers)

however doing a borehole of 50ft deep. is more of a deterrent. and also cheaper to bore and bury without leaving a tombstone marker to give away where the treasure is

just saying

[hosseinimr93]

This seems somewhat terrifying if we consider that this hypothesis is possible if a paper wallet is used with a single address and key. This brings us to the conclusion that using this method of storage is very dangerous without the user having the necessary technical knowledge.

As I already said, there shouldn't be any problem since your wallet should send back the remaining balance to you.
What I said about not specifying the change address when making the raw transaction applies to any transaction, not only spending from a paper wallet.

[bormi]

paper can get wet/burn, decompose, ink fades

try drilling/ etching into metal

using seed phrase. you can drill out holes for each word

just the first 4 letters can tell you the word
so
      A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z
1    x
2        x
3    x
4                                                       x
=ABANdon
do for all 12-24 words

or its words numeric position in the known word library
     0  1  2  3  4  5  6  7  8  9
1   x
2   x    
3   x
4       x                                  
0001=abandon
do for all 12-24 words

metal lasts longer is fire proof and damp proof

...
the good thing about keys is that your are not limited to one storage. one format of said storage. so dont feel limited to one type

*Sorry for my translation into English via google

I give my vision.

A) Offline auto mode and with usb live
1-With a secret word, generate a SHA-256 hash-o phrase (eg mother's love) https://xorbin.com/tools/sha256-hash-calculator
2-Generate a seed phrase of 24 words https://iancoleman.io/bip39/
3-If you have hair on your head (or in another private place), you shave your hair to zero.
4-The secret word is tattooed under shaved hair.
5-Letting hair grow

*To obtain 8 seed phrases derived from the same 23 words, Convert the words to decimals and give 256 bits. The last three bits are changed. For example, if they use 253 bits and the last 3 will oscillate between 000 and 111 (8 possibilities) and 8 seed phrases can be obtained,
Then save as Franky1 indicates a super backup copy.
Even metal can be marked in binary

To make more entropy with the SHA-256 obtained. It can be done as many times as you want. For example:
bormi = d696f210b808e584b12ecc5c4ae2596bf5925b920b96c27d913f734459438f
Then another SHA-256 give this result = d113a18bb3c67083920dd0241cae876610f32b73bbe35de26c1166dc180910c3
So the secret word would be bormi*2

[LoyceV]

3-If you have hair on your head (or in another private place), you shave your hair to zero.
4-The secret word is tattooed under shaved hair.
5-Letting hair grow

Your tattoo artist is going to love it!

[n0nce]

My opinion on this: you mentioned Ledger - absolutely avoid. It is closed-source and relatively low-grade build quality, so I'd neither trust its key generation, nor that it will function in 20 years.

What you want is a securely generated seed phrase and storing it safely.

As for part one, I'd recommend using something like a hardware wallet with open-source software and (!!!) hardware, so you can be sure there is no funny business going on with key generation. Alternatively, roll dice. In that case, you need an offline, airgapped PC with Electrum; for that, just get a copy of Tails and follow for example this guide.

For safe storage, I'd probably do a few Steel Washer backups and store in different locations. Choose material to your liking (e.g. anti corrosion or whatnot) and if you want, test those properties before deploying the backups.

Do make sure to verify your backups before sending 0.5BTC to the wallet. To do this, note your first address in the newly created wallet. Then reboot the PC, import wallet in Electrum, enter the seed words from your backup and check whether the first address matches. Feel free to do this a few days later, when the phrase has fully left your memory.


Since this has been mentioned: plausible deniability is definitely your best friend. Try to minimize the number of people knowing you own / buried BTC and the number of people seeing you do it (preferably both equal to zero).