Writing down seed phrase: printer ink or pen ink ?

[o_e_l_e_o]

Not only unnecessary; I personally find it worse. Metal detectors can detect those.

I can only imagine this being a concern if you are planning to bury your seed phrase outside somewhere. If you store it inside your house or other building, inside a safe, in a safe deposit box, etc., then metal detectors become useless due to the presence of copious amounts of metal in the close vicinity. Stainless steel also happens to be one of the hardest metals to accurately detect using a metal detector since it displays very low levels of magnetic permeability.

[1715514022]

1715514022

[1715514022]

1715514022

[1715514022]

1715514022

[1715514022]

1715514022

[1715514022]

1715514022

[1715514022]

1715514022

[PrimeNumber7]

If you are comparing storing a backup using medium A and medium B, in order to compare the two mediums, you need to assume the same security measures are taken, unless doing so would not be possible.

If you are comparing which storage medium is more secure once they have been created, then sure, you assume they are both created securely. But in reality, that is not the case. Almost anyone can write down a seed phrase securely - just make sure you do it with nobody else around and no cameras or webcams pointed at what you are doing. Very few people on the other hand can properly create an encrypted USB drive back up from a properly airgapped computer, leaving no traces of what they have done and leaking no information in the process. This is an important point to consider.

Writing down a seed still requires some kind of computer-like device to generate the seed. If the seed was generated on a HW wallet, then perhaps storing a seed on a USB drive would require an additional computer. However, if you remove that assumption, using a USB drive requires no additional security measures above using a paper backup.

Just as if we compare a properly created paper wallet to a properly created software wallet, then the paper wallet is exponentially more secure. However, we know from experience that many people who create paper wallets or import them later do insecurely because they far harder to create and use than a simple software wallet.

This is not true. I am assuming you are referring to a wallet that is not a hardware wallet.

If you compare the potential security risks associated with creating (and using) a paper wallet, and a wallet stored on an encrypted hard drive or USB drive, using a paper wallet would have all the security vulnerabilities associated with a seed stored on an encrypted hard drive or USB drive, and would also have additional security vulnerabilities.

Every medium of storage has the potential for data loss under certain circumstances, and the only way to mitigate this risk is to use multiple storage mediums.

This is also mitigated by using multiple storage locations, not just mediums. If the circumstance is, for example, all my paper wallets are vulnerable to fire or water damage (which is no different to a USB drive), then I am far safer storing two paper copies in two physical locations in different states than I am storing a paper and a USB copy a few blocks from each other.

I will advise people to follow the 3-2-1 rule:
3 backups using
2 mediums of storage, with at least
1 backup stored off-site

When comparing your two choices, you are changing two variables, the number of mediums of storage and the distance each backup is located from the other. The variable that increases the benefit in your comparison is the distance between backups, not using a single medium of storage.

[o_e_l_e_o]

Writing down a seed still requires some kind of computer-like device to generate the seed. If the seed was generated on a HW wallet, then perhaps storing a seed on a USB drive would require an additional computer. However, if you remove that assumption, using a USB drive requires no additional security measures above using a paper backup.

The only time you need no additional equipment to create an encrypted USB is if you are using a software wallet on a computer, and even then there is additional risk in taking a seed phrase out of a password protected wallet file and saving it in plain text in a text file. These risks are mitigated if you are using a properly and permanently airgapped system, but we both know that very few people do that and do it properly. If you are using a mobile wallet or a hardware wallet, then inputting your seed to a computer to create an encrypted USB back up is significantly riskier than writing down your seed phrase on paper.

If you compare the potential security risks associated with creating (and using) a paper wallet, and a wallet stored on an encrypted hard drive or USB drive, using a paper wallet would have all the security vulnerabilities associated with a seed stored on an encrypted hard drive or USB drive, and would also have additional security vulnerabilities.

I am comparing a properly created paper wallet (airgapped device, dumb printer, etc.) and a hot software wallet. Properly used then the paper wallet is exponentially more secure, but we both know that many people do not use them properly.

I think it is disingenuous to say "Well, if you do it properly then printing your seed phrase is fine", when we know that the vast majority of people will not or can not "do it properly". Far harder to make a critical error when writing down your seed phrase than when printing it out.

The variable that increases the benefit in your comparison is the distance between backups, not using a single medium of storage.

My point exactly. The important point of your 3-2-1 rule is at least 1 back up stored off-site (although I would argue for more than this if you can safely do so).

[Peanutswar]

I store mostly my seed in a safe place because I wrote it down on a piece of paper, printed in a bond paper, and make an online copy to make sure I have different copies in case I miss out or forgot my seed of course no one memorizes their seed also it's ideal if you bought a hardware wallet to you have another layer of security that each transaction must need to require with the HW verification.

[BitcoinGirl.Club]

Does not matter. Laminate.

Or do some DIY.
I bought a metal plate. Changed some words the way I can remember them. They are some synonym or antonym which I know. Did not make it complicated obviously. Then I lesser printed it and it's fire proof. There are two copies and only these two copies combined will get the full seed.

I feel fairly safe LOL

[o_e_l_e_o]

The problem here is that you want to make your seed phrase resistant to loss, but also resistant to theft.

I store mostly my seed in a safe place because I wrote it down on a piece of paper, printed in a bond paper, and make an online copy to make sure I have different copies in case I miss out or forgot my seed

So this set up with multiple back ups in different medium is very resistant to loss, but not very resistant to theft. Storing your seed phrase online is usually a terrible idea and huge security risk. We have seen seed phrases been stolen from email accounts, cloud storage, websites, file servers, you name it. If it is online, it is at risk. I hope that you have strongly encrypted whatever you are storing online, but it would be far better to not do this at all.

I bought a metal plate. Changed some words the way I can remember them. They are some synonym or antonym which I know. Did not make it complicated obviously. Then I lesser printed it and it's fire proof. There are two copies and only these two copies combined will get the full seed.

And this suffers from the opposite problem. From what you've written, it sounds like you have two metal plates but with half the seed phrase on each. There is no redundancy in this set up. You have two back ups, and you need them both to recover your coins. The loss of a single one of your back ups results in loss of your coins. Forgetting what words you have changed could result in loss of your coins. It is resistant to theft, but it is not very resistant to loss.

[larry_vw_1955]

Does not matter. Laminate.

Or do some DIY.
I bought a metal plate. Changed some words the way I can remember them. They are some synonym or antonym which I know. Did not make it complicated obviously. Then I lesser printed it and it's fire proof. There are two copies and only these two copies combined will get the full seed.

I feel fairly safe LOL

Laser printing isnt fireproof. So i'm not sure what you mean.

[Pmalek]

I bought a metal plate. Changed some words the way I can remember them. They are some synonym or antonym which I know.

Check out the bolded parts. Words that YOU can remember and words that YOU know. With time, your memory can start playing tricks with you. Those who suffer from Alzheimer's can't recognize their children or remember where the bathroom is in their home, let alone remember what antonyms or synonyms they used and where. It might seem like a good idea now, but who knows that the future holds.

Does your family know the words YOU remembered and the antonyms/synonyms YOU used? What if you die or suffer a serious head injury? What if war comes to your doorstep overnight as it did to Ukraine?

[larry_vw_1955]

I bought a metal plate. Changed some words the way I can remember them. They are some synonym or antonym which I know.

famous last words of someone that is trying to be "clever". it will bite them in the rear end more often than not 

[BitcoinGirl.Club]

Check out the bolded parts. Words that YOU can remember and words that YOU know. With time, your memory can start playing tricks with you. Those who suffer from Alzheimer's can't recognize their children or remember where the bathroom is in their home, let alone remember what antonyms or synonyms they used and where. It might seem like a good idea now, but who knows that the future holds.

Does your family know the words YOU remembered and the antonyms/synonyms YOU used? What if you die or suffer a serious head injury? What if war comes to your doorstep overnight as it did to Ukraine?

Fuck you man! You are scaring me to death.

This did not came to my mind. Good point. The family only knows the two separate set that needs to bring together but they do not know about those tweaks on few words. I may need to plan to let someone know about it.

Take the F word easy man. No homo 😘

[o_e_l_e_o]

Laser printing isnt fireproof. So i'm not sure what you mean.

It sounds like he lasered the metal plates. I hope he has his own equipment for doing that and didn't hand his seed phrase over to some third party vendors to laser it for him.

This did not came to my mind. Good point.

I would suggest that if an attacker has been able to either find out enough to figure out the location of two separate back ups, or coerce you to revealing the location of these two back ups, then one or two changed words will not pose much of an issue for them, and they can either work out, brute force, or coerce the correct seed phrase. A far better option would be to use one or more additional passphrases (although again, make sure someone else knows what these are or how to recover them), which provides greater security as well as plausible deniability.

[BitcoinGirl.Club]

I would suggest that if an attacker has been able to either find out enough to figure out the location of two separate back ups, or coerce you to revealing the location of these two back ups, then one or two changed words will not pose much of an issue for them, and they can either work out, brute force, or coerce the correct seed phrase. A far better option would be to use one or more additional passphrases (although again, make sure someone else knows what these are or how to recover them), which provides greater security as well as plausible deniability.

The people I am surrounded with are not much bitcoin savvy not even tech savvy. I am not sure if I am underestimating them but it seems whatever you do, is not enough always. This additional layer is interesting. At this moment I have 3 people who needs to be contact each others to find the full combination. Among three, two are common relative who are very trustworthy to me. The third one will be able to connect with one of the relative to send the message only in case any accident happens to me.

[PrivacyG]

The people I am surrounded with are not much bitcoin savvy not even tech savvy. I am not sure if I am underestimating them but it seems whatever you do, is not enough always. This additional layer is interesting. At this moment I have 3 people who needs to be contact each others to find the full combination. Among three, two are common relative who are very trustworthy to me. The third one will be able to connect with one of the relative to send the message only in case any accident happens to me.

From my understanding, this is a 3 out of 3 setup.  I see this as yet another problem.  If the connection between THREE persons is necessary in order to find the full combination, have you considered other possible issues they could encounter in the event of you losing your life?  It is not very rare that after the loss of a loved one relatives start arguing about what the deceased has left behind for the living ones.  Some are more greedy than others.  The trust you have in your relatives may not be equal to the trust these relatives have for each other.  What if you die together with one of these three persons that are NEEDED for the recovery of the seed?  What if the third person will request a premium for sharing their key part of the puzzle?  You have ensured the recovery if an accident happens to YOU, but you have not taken into account the possibility of an accident also happening to one or more of them.

As others have pointed out, I would keep the seed phrase backup as simple yet safe as possible without reinventing the wheel.  I would definitely not rely on humans for the recovery.  There is maybe more vulnerability to three humans having to connect for the combination than there is for an improperly stored paper wallet.  It is enough for one of the three to say 'no' and now everything goes wrong.

I remember Trezor offered a backup method that requires 'x out of y' backup sheets with a variable x or y based on your needs.  I can not remember the name of this method however, although I do think the name was something similar to 'Schnorr'.  Maybe someone with more knowledge can help me with the confirmation that this method is safer and less vulnerable than a 3 out of 3 sheets setup?

-
Regards,
PrivacyG

[o_e_l_e_o]

I remember Trezor offered a backup method that requires 'x out of y' backup sheets with a variable x or y based on your needs.  I can not remember the name of this method however, although I do think the name was something similar to 'Schnorr'.  Maybe someone with more knowledge can help me with the confirmation that this method is safer and less vulnerable than a 3 out of 3 sheets setup?

Are you maybe thinking of Shamir's Secret Sharing Scheme? It essentially splits your seed phrase in to encoded shares (which can also be expressed as a series of words if you desire), which you then share among your friends or relatives. As you say, you can choose any x-of-y set up, provided that y is equal or greater than x. So I could do a 3-of-5 for example, where any 3 shares out of the 5 I generate is sufficient to recover my seed phrase, and the knowledge of any number of shares less than 3 provides no information about my seed phrase.

It sounds great on paper, but in reality there are a number of significant security risks with it, such as flawed implementations, no universal standard, and a single point of failure. There is a good article about why you shouldn't use it here: https://en.bitcoin.it/wiki/Shamir_Secret_Snakeoil

In reality, if you want an x-of-y set up, then you should just use a multi-sig wallet.

[dkbit98]

I remember Trezor offered a backup method that requires 'x out of y' backup sheets with a variable x or y based on your needs.  I can not remember the name of this method however, although I do think the name was something similar to 'Schnorr'.  Maybe someone with more knowledge can help me with the confirmation that this method is safer and less vulnerable than a 3 out of 3 sheets setup?

This is called Shamir Secret Sharing scheme and it is used by Trezor Model T, Keystone hardware wallets and I think Airgap wallet is using something similar.
I consider this to be poor man alternative to multisig setup, and this is not safer in any way compared to multisig, with one big flaw single point of failure.
You can see comparison for this two methods with more details in my topic Multisig VS Shamir Secret Sharing.

[BitcoinGirl.Club]

From my understanding, this is a 3 out of 3 setup.  I see this as yet another problem.  If the connection between THREE persons is necessary in order to find the full combination, have you considered other possible issues they could encounter in the event of you losing your life?  It is not very rare that after the loss of a loved one relatives start arguing about what the deceased has left behind for the living ones.  Some are more greedy than others.  The trust you have in your relatives may not be equal to the trust these relatives have for each other.  What if you die together with one of these three persons that are NEEDED for the recovery of the seed?  What if the third person will request a premium for sharing their key part of the puzzle?  You have ensured the recovery if an accident happens to YOU, but you have not taken into account the possibility of an accident also happening to one or more of them.

As others have pointed out, I would keep the seed phrase backup as simple yet safe as possible without reinventing the wheel.  I would definitely not rely on humans for the recovery.  There is maybe more vulnerability to three humans having to connect for the combination than there is for an improperly stored paper wallet.  It is enough for one of the three to say 'no' and now everything goes wrong.

I remember Trezor offered a backup method that requires 'x out of y' backup sheets with a variable x or y based on your needs.  I can not remember the name of this method however, although I do think the name was something similar to 'Schnorr'.  Maybe someone with more knowledge can help me with the confirmation that this method is safer and less vulnerable than a 3 out of 3 sheets setup?

-
Regards,
PrivacyG

Need to study the Shamir's Secret Sharing Scheme. I was thinking it was good enough only to split the seed to two person but then I had to involve another person to answer the twisted words. The only thing I am lacking here is one of the person lives with me who is holding half of the seed. Means if in our house by any chance if we both become a victim of a sudden accident then the one who has other half of the seed will not find anything. He can not access the fund.

Not yet going to apply but this is what I am thinking now.
First half of the seed goes with 1. The person who lives with me together (my wife) 2. One in-law I have.
2nd half of the seed is going to 1. The person who currently have the half (my sibling) 2. A cousin from my side
The person who is responsible to break the twist is close to me but not close or better say very much known to any of the person who have part of the seeds.

It is now involving 5 people. Two of the one half know each others but they have same words, the other two of the other half also know each others but again they have same words. The 5th one will only trigger if something happen to me or even something happen to me and my wife together.

[LoyceV]

Need to study the Shamir's Secret Sharing Scheme. I was thinking it was good enough only to split the seed to two person but then I had to involve another person to answer the twisted words. The only thing I am lacking here is one of the person lives with me who is holding half of the seed. Means if in our house by any chance if we both become a victim of a sudden accident then the one who has other half of the seed will not find anything. He can not access the fund.

Have you considered Split mnemonic cards?
Example:

Code:

Card 1: under stomach XXXX XXXX XXXX XXXX dust struggle ugly XXXX rocket XXXX hedgehog sponsor produce hello border limb appear mixture XXXX peanut live XXXX
Card 2: under XXXX peace humble weather flip XXXX struggle ugly dinosaur XXXX voyage hedgehog sponsor XXXX hello XXXX limb XXXX XXXX ladder XXXX live normal
Card 3: XXXX stomach peace humble weather flip dust XXXX XXXX dinosaur rocket voyage XXXX XXXX produce XXXX border XXXX appear mixture ladder peanut XXXX normal

This shouldn't be used with less than 24 words, and I've read more reasons not to use it, but it's a lot easier to understand than Shamir's Secrets. Either 2 out of 3 Cards are enough to restore the seed.

It is now involving 5 people.

This sounds overly complicated.

[o_e_l_e_o]

Need to study the Shamir's Secret Sharing Scheme.

Don't waste your time. As has been explained above, it is a poor choice with significant flaws and should not be used.

Your suggested set up is better because you now have some redundancy in the system, but it still seems overly complicated to me and if it were me I would still prefer to use a 3-of-5 multi-sig set up.

[larry_vw_1955]

Your suggested set up is better because you now have some redundancy in the system, but it still seems overly complicated to me and if it were me I would still prefer to use a 3-of-5 multi-sig set up.

I second the suggestion to use multisig. People take it for granted here in bitcoin but some cryptos can't do it for example ethereum. multisig can increase transaction fees slightly but ... it's no big problem.

[pooya87]

I second the suggestion to use multisig. People take it for granted here in bitcoin but some cryptos can't do it for example ethereum. multisig can increase transaction fees slightly but ... it's no big problem.

You can technically create a Tapscript where you use multiple keys to sign but only publish one using OP_CHECKSIGADD which is a new OP code added in Taproot soft-fork. That way the cost of multi sig is the same as any other single sig transaction.
The problem is that there still isn't any user friendly way of doing it since wallet developers are behind in their implementations.