Bitcoin Forum

Many have discussed duress PINs and BIP-39 passphrase decoy wallets. I am actually asking about a different model here: a registered fake private key that a custodial/back-end system recognises and intercepts thereby simulating success to an attacker while preventing actual on-chain movement. Is this technically feasible?

For example, a BTC holder is abducted and instructed at gunpoint to release his private key or perform a BTC transfer to any BTC wallet, he gives out the fake key or enters it to do the transfer but the system recognises the security threat and seemingly allows the transfer to occur but in reality it is only a fake transfer due to the fake code, so when transactions are signed with a registered fake key, the backend intercepts/flags them and simulates success for the attacker while preventing actual irreversible movement.the system is notified that this is not a real transaction and play along. I wonder if this can be implemented or not.

The major setback I will admit here is that this can create rooms for holders with devious mindsets to perform such transactions for fraudulent purposes.
So the question would be about what technical measures that can be in place to avert such abusive attempts. I am thinking of a possible solution that fits this puzzle but I am inviting everyone to give their thoughts.

Could this be possible? please I am open minded.

No, I'm sure core developers would decline this because you give scammers an opportunity to use this for scamming.

Look at the double-spend attack that most of the scammers use.
That's why most of the merchants nowadays release their product only after the 3 confirmations.

If this is not feasible in any way, how about another approach like: Opening a parallel account which will contain fake BTC's that can actually be moved to the culprit's account but totally useless? This is just to provide relief for the abducted BTC holder to save his life. The system must be programmed to play according to this script under such circumstances.

Yes it does save life and in another way can be used to deceive others by the same scammers and so not good.

A good security method should be able to protect one from both scammers/thefts in both ways in order for it not to make victim for another.

There are lots of fake BTC but not on the mainnet.
So your plan that you want to implement is possible in your own network and also if you can make a fork version of BTC.

It only works if you are hosting them online and try to convince them to use your server. So that you can send them fake BTC that's available only in your server.
Look at those altcoins like LTC, which is a fork version of BTC. So if you can fork BTC without changing the names, then you can have your own server with fake BTC.

First: What is "the system"? The device of the victim? In this case of course you can build any kind of fake wallets and fake Bitcoins, even without network connection at all. You could also connect to a "copycat" altcoin network with the same BTC address format and transact these worthless altcoins around.

But if the thief's wallet should register the transaction, then your feat becomes impossible. Fake bitcoins stay fake.

You could however come close with some Bitcoin Script creativity:

- You could transfer the BTC with a timelock far in the future. The thief's wallet however would not see this transaction because Bitcoin clients do not accept transactions with timelocks in the far future. But you can show him a screenshot of your transaction going out.
- You could transfer your BTC to the thief with a transaction with a CLTV or CSV timelock and an alternative path to spend them. The thief would "see" the transaction on his wallet, but he can't move the coins until the timelock has passed. If the thief goes away satisfied or you can escape before the timelock ends, then you can move the coins back. Everything depends however how the wallet shows this transaction.
- The thief however could always detect the timelock, and if he knows about Bitcoin, held you in captivity until the timelock ends. "Perhaps", in the future if covenants (https://bitcoinops.org/en/topics/covenants/) become a thing, you could specify some condition that the thief, regardless how much he moves his coins, always will have to move them to a script which allows yourself to move the coins back. This would basically be an Ethereum-style smart contract. I'm unsure about that though.

"Fake bitcoins" cannot be used for scamming, BitMaxz is wrong here. In theory a contract like I describe above can be used for that but a merchant should be able to detect that.

You can just have a real wallet with some small amount.

They are called "test coins". You can pick testnet3, testnet4, signet, or regtest. The problem with testnets is that they are worth non-zero amounts, so they are no longer "fake". But yes, nothing stops you from using an altcoin, which would be based on Bitcoin, for example BCH, and pretend to believe, that "BCH is Bitcoin", and when you said "I have one Bitcoin", then you meant "1 BCH", instead of "1 BTC".

Yeah, many people forget, that we are here in a P2P world. If your only goal, is to see something in some block explorer, or a site like that, then it is easy. It is then only about making a web page, that could display you anything. It could even say, that you have more than 21 million coins, because why not.

That's why the simplest solution is to have a separate wallet with some small amount. And you can even use different units, like mBTC, or bits, or even count everything in satoshis, if you want to.

Yes, and send it through https://live.blockcypher.com/btc/pushtx/ because they can accept it, and display it, and even say, that it has something like 20% probability to be included in the next block, even if you timelock it to 10 years.

It is probably better to show a buggy block explorer, like the one linked above. But I guess there are more buggy ones, and another one can be made, if the operators of this specific one will decide to ever fix it.

This is hard to do, because adding opcodes (like OP_CLTV or OP_CSV) makes the whole thing Script-based, and not key-based. And if you alter a single bit in the output Script, then you will get a different address out of it.

But yes, if someone is using Script-based addresses, then "<lockConditions> OP_CODESEPARATOR <normalConditions>" is a good envelope to use, because then, you can pretend, that the output Script is set to just "<normalConditions>", and sign it properly.

I guess many people were scammed, by buying test coins, at the price of Bitcoin, or even bought BCH or BSV, thinking they are buying BTC.

That's not how Bitcoin works. Bitcoin is decentralized and transparent. The attacker can technically be using a normal wallet that connects to the real chain and monitors it for incoming transactions. You cannot fake a transaction on real bitcoin network!

That's another problem. Someone at gunpoint is not going to hold back, and maybe holding back is not a good idea!

Prevention is better here. People should not let others know how much money they have in first place to avoid putting themselves at the other end of a gun to need to make a decision.

Test coins are useless because the relevant addresses differ from those associated with the mainnet. :( This means you can't send your test coins to the address that scammers provide. Those involved in crypto-related crimes are often highly skilled, and the chances of tricking them are almost zero. If they catch on that you're trying to deceive them, things could end badly for you

First of all, there's no such thing such as "account" on Bitcoin protocol/network. You can't have fake BTC on Bitcoin network, since whole blockchain verified by each node. Any decent wallet also perform partial verification.

But on theory, you could create and use alternative network that contain "BTC". The "BTC" is fake, although the network actually exist and your wallet can make the transaction. But it wouldn't fool criminal whole check balance of the destination address using block explorer website.

I see this as a clash between human safety and blockchain integrity. On one hand, a duress feature could save someone’s life but on the other, it could open doors for scammers to misuse it. Maybe the middle ground isn’t changing the protocol but creating optional wallet apps that simulate a convincing interface under duress while protecting the real funds elsewhere. That way, the blockchain stays clean but users still have an extra layer of defense in critical situations.

Another idea that I think could work better is a personal-level solution. Like having a decoy wallet with a small balance that looks real enough to satisfy an attacker. That way, you don’t tamper with Bitcoin itself but still have a way to survive under pressure.

Read the OP first paragraph he is definitely not interested in the wallet decoy of creating a passphrase and storing some bitcoin on the seed phrase without passphrase, he wants something to share with the bitcoin network or miners like a script that the transaction was done under duress and should be reversed later. Which looks impossible to me not because it’s not possible but because once this will be used for something else, wasn’t it a good development when RBF was included only for people to start abusing it and prompting receivers to actually start having threshold of number of confirmation needed,

For me there is nothing like a fake BTC and having a script like this is also bad, even the time lock is actually putting your life in danger because the criminal will be able to find out and puts your life in danger, as long as the criminal already knows you even hold bitcoin forehand is a definitely risky to even try out any of these tricks because you of my know his dept of knowledge seriously

How about a normal measure that you shouldn't broadcast your wealth
Or that funds shouldn't be placed in one wallet. At least have an Hot wallet for quick transaction.

And even if there's a system that can automatically protect your funds
It wouldn't protect One from the hands of the criminal
Imagine what they would do when they found out they have been played.

The best is not to broadcast your wealth or have a 'sacrificial' wallet Incase such a Cass arise.

Or carry a weapon so that you don't get into this situation in the first place!

With Bitcoin appreciating, it should be difficult to acquire and learn how to use a pistol.

Anything implemented that can fool a "culprit" can also be used to fool a merchant.  If the merchant can tell it's fake, then so can the "culprit".  If the "culprit" can't tell it's fake, then neither can a merchant.

So, to protect yourself from sending bitcoins when you don't want to, you force others to accept fake bitcoins when they don't want to.  That does not sound like a solution to me.

Nah... this is one scary advice. Using weapon as self defense may not help you avoid casualty or being victimized, assuming both you and the attackers are armed.

You can have a different wallet with smaller amount of Bitcoin in it, the main wallet will be totally offline, not in any device, you only will lose that little instead of risking yourself.

If we all come to think about this very well it actually makes sense, this can settle negotiation with terrorists and kidnappers who are putting innocent lives at risk of getting shot, but unfortunately bitcoin was not build with this idea in mind so therefore it is not going to work.

I am somehow glad that this won't work not because i like seeing innocent people lose their lives at gun point but because of what criminals will start doing if such idea was available in bitcoin from day one, they will buy gold and make fake transfer, they will commit biggest and easiest robberies around the globe with it, if you think about it very well you will see that this idea with bring us more damages than good.

The best advice i can give every bitcoin holders is to be security wise, avoid telling people about your portfolio and also avoid showing the world that you are a big holder, be a casual dresser and watch your mouth, you are free to live a flamboyant life if you want but make sure you put your security first and that of your family.

Even if such a simulation mechanism (for fake bitcoins) were developed, you would still have to count on the time it takes for the crook to discover he was been deceived. Even if you gainenough time to get away from fim/them (the danger zone), if he know where you live or where you frequent, they'll come after you. You've only prolonged the danger. tictac. Of course, it all depends on how targeted you have become, the attacker's motivation, the amount of money you have, the sanity of these guys, etc.

As other people have said here, it's better to prevent than to cure. If people in your circle ask about Bitcoin, tell them you're only in Bitcoin for the technology and not for the profit lol.

I think that from the moment a gun is pointed at my head, Bitcoin will be the least of my problems, your life is worth more than the money you have.

Even if they rob you of everything and you manage to get out alive, your chances of rebuilding your life and assets (or just part of what was stolen) are greater than if they take your life at the time of the extortion.

Summary: don't let anyone find out how much Bitcoin you have. If they do, create a decoy wallet. There are several methods available, so study them. If they still discover your decoy wallet, don't hesitate to try to fool the crook a second time, because you know what can happen.

As others have commented anything like your proposal can be widely abused and innocent
people could get caught.

I think the best option is a decoy. [again as others have posted]

Buy the cheapest hardware wallet you can get or use a hot wallet on your phone.
I would also suggest to create "fake" transactions made by yourself on that
wallet, especially now that the fees are so low, spend a few weeks sending and receiving
sat's from the decoy while all the while leaving something like IDK $100 in the wallet and
make sure to make a transaction regularly to build a history.

You have to consider that your attackers might be well versed in Bitcoin and might well
be able to check for a timelock and might check your wallet to see if it is "live".

I would definitely be of the opinion of giving them something rather than nothing in order
to preserve my life. Trying to trick them with a timelock or test coins might very well get you
killed for the sake of $100, $1000 or even $10,000 which depending on your overall HODL'ing
could be a very small percentage.

Showing off your hardware wallet or simply walking around the beach with it is a great way to become an easy target. The ledger has a hole for you to attach a lanyard to it, like a keychain or neck lanyard.

Definitely avoid this! I recommend leaving your hardware wallet at home, especially if you live in a country where access to weapons is restricted by the government and is a violent country.

People who aren't familiar with BTC will likely assume that someone carrying a hardware wallet has a lot of bitcoins, which isn't always true.

That makes sense - but I didnt advocate for any of that. I think you misunderstand
my quoted text.

What you're saying here will cause more problems than the solution you believe it will create.
Years ago, if we once saw a situation where testnet coin was used to scam merchants and newbies, there's nothing preventing scammers from using the strategy you propose to scam a lot of people.
If any Bitcoiner wants to safeguard themselves from duress that could jeopardize their BTC, it is better to prioritize privacy and avoid human error.
 
If you're thinking about a solution to an issue, always think about the consequences that come with it.

compared to the number of existing bitcoin users, the kidnapping problem is minimal collateral damage, I think there is nothing viable to do through software, the best thing that can be done to combat this type of crime is to educate people so that they do not walk around with a sign on their forehead that says "I have bitcoins" , because if nobody knows that you have bitcoin or how much bitcoin you have, most likely nobody will try to take it from you, and in the event that it is inevitable that people find out, the only thing I can recommend is to have several wallets, one as a decoy and another with the rest, the decoy should have enough funds to make it look real and not suspect that there are more, but not all your capital.

Sorry, I know you didn't advocate any of this, just to clarify, it was just an addendum I thought was important. Don't worry  :D

Exactly, the Bitcoin protocol through BIP38, 39, BIP85, etc. already enables several functionalities, as well as other external open source encryption tools.

you could have the 10 coin key real  used with big wallet


and a 1 coin key real but just a fraction of your coins used with small wallet

the robbers would figure 120K nice score.

you would still have the 10 coins in the other wallet.

Actually yeah your registered fake private key system may be technically feasible but only within a centralized custodial environment like an exchange or a centralized back end service. It simply wouldn't work with a self custody wallet broadcasting directly to the decentralized bitcoin network as there's no intermediary to perform any form of interception and simulation.
As little as the double spend feature it's already being abused plus all these things don't  really align with the authenticity of coins based on the bitcoin protocol.

On hardware wallets like Ledger you can set a "double pin", which means you can have the device unlock on 2 pins with each one linking to another wallet. The idea is that the same seed phrase is used, but depending on the pin used to unlock the device, there is an extra type of salt or "password" ontop of it.

I assume the same can be done with software wallets, where your 24 word seed phrase is holding a "password" to obscure the real funds.

You would hold assets in the 'naked' 24 seed phrase but keep the real big funds on a "password" protect one. You may even use a "system" that monitors the blockchain for the naked seed phrase and perform an automated sweep of the password protected when a certain amount of naked assets has moved.

Alternative, you may lock up coins in HTLC or similar type of tx. You commit to locking up X coins and unlock them at any time by using the spend tx. Attackers may not be skilled enough, or lack the resources to scan every blockchain for HTLC type of transactions.