Fees are low? Make your coins more private and (almost) quantum safe!

[d5000]

Low fees of 1 or 2 satoshis per vByte are an excellent opportunity to make your coins more safe and private. You can even make them almost quantum-safe - in 2025!

Well, in many cases, you may already have done your homework. But if not, then this post ist a reminder


New bitcoiners often make a mistake: they often re-use their Bitcoin addresses. Some think that a Bitcoin address is kind of an "identity", or an "account", like some altcoin communities like Ethereum's told them. But that is not the case!

Bitcoin is best used without re-using addresses. [1] There are two main reasons:

1) Re-using Bitcoin addresses make it easier for any entity, for example chain analysis companies, but also thieves and scammers, to link your coins together. In short: Your privacy is at risk! (See also this post).

2) When you spend coins from an address, you expose your public key for this address and store it to the blockchain. In the future, this may enable attackers with quantum computers to compute the private key using the public key and steal your coins! [2] [3]

There's an easy fix: simply move the coins on the re-used addresses to a freshly generated address! Both Bitcoin Core and the popular SPV wallets like Electrum or Sparrow provide easy means to do that.

1) Simply select the tab or menu item where your addresses are shown.

2) Select an address which was not used. In Electrum for example, you see the number of transactions made with this address under the column "Tx". If it is zero, then you can use this address.

3) Copy this address.

4) Now you have two options to spend them:

4a) If you have coin control enabled, then it's best to separate the coins according to the address where you received them. Select all coins which are on the same address, add them to coin control, and then send all these coins to a fresh address.

4b) If you don't have coin control enabled or don't know how to use it, or you have only one or two re-used address(es), then you can simply send all the Bitcoins to the fresh address.


Note:

There is a special class of re-used addresses: those where you only received coins, but never spent them. This is typically the case in bounty campaigns when you decide to hodl all rewards.
It is a good idea to eventually move these coins to a fresh address too, but in this case it is best if you then never use this address again. So if you want to continue to hodl the coins which arrive in this address and not spend them, it's not necessary to move them.

Note 2:

If you for any reason still have coins which were received with a P2PK script, i.e. paid directly to a public key instead to an address, move them too! This is often the case if you mined in the early years of Bitcoin. They're not less private, but they are vulnerable to quantum computing attacks just like coins on re-used addresses. It's unlikely you're a beginner in this case though


[1] Well, there are some cases where re-using addresses is convenient, for example if you participate in a bounty campaign. Even veterans often forget to move these coins to fresh addresses, too! But it's always a good idea to regularly move coins from re-used addresses to fresh ones.

[2] In theory, once quantum computer technology has advanced to the point where keys can be calculated in less than an hour, even your coins on addresses that were never re-used can be stolen. But first, this would require insane quantum computing power. And second, it's likely that at this date there will always be quantum-safe addresses available.

[3] There are proposals to burn or re-distribute "vulnerable" coins should quantum computers become a problem. Coins on re-used addresses could be considered "vulnerable". Moving them to an un-used address NOW would save your coins from being burnt because you forget about them in the future!


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[dzungmobile]

Low fees of 1 or 2 satoshis per vByte are an excellent opportunity to make your coins more safe and private. You can even make them almost quantum-safe - in 2025!

Well, in many cases, you may already have done your homework. But if not, then this post ist a reminder

Newbies don't know about this trick on consolidation inputs when mempools are clear, and transaction fees are cheap. They don't know about mempools, don't know about fee rates like relying on centralized exchanges in bitcoin storage and withdrawal for transactions, don't know about a fact that cheap transaction fees won't last forever.

Minimize your transaction fee with Electrum wallet.
Guide on consolidation of small inputs and update on mempool status.
All about transaction fees in Electrum.

There is a telegram bot to track Bitcoin transaction fee, if they don't want to observe Bitcoin mempools with Bitcoin mempool observing sites.

[Telegram Bot] Bitcoin Fees - fees and tx tracker

More advanced guide on Bitcoin privacy.
https://bitcoiner.guide/privacy/

[NeuroticFish]

Newbies don't know about this trick on consolidation inputs when mempools are clear, and transaction fees are cheap. They don't know about mempools, don't know about fee rates like relying on centralized exchanges in bitcoin storage and withdrawal for transactions, don't know about a fact that cheap transaction fees won't last forever.

Indeed, most don't know and most don't care, for the reasons you've mentioned, plus that seeing how expensive it is to withdraw from any CEX they will use wrapped bitcoin and other altcoins.

However, this has the potential to help some - few, who actually want bitcoin, who maybe missed this or that bit of information - hence I still find it a good idea to write it down (now and then), no matter how small the number of them is.

[Zaguru12]

New bitcoiners often make a mistake: they often re-use their Bitcoin addresses. Some think that a Bitcoin address is kind of an "identity", or an "account", like some altcoin communities like Ethereum's told them. But that is not the case!

Bitcoin is best used without re-using addresses

But if we seriously discuss about address been re-used which kind of exposes one privacy  then the idea of consolidating of fees will still be another thing, because consolidating your coins will simply just link them together as one, but most of the time it is usually same thing since you will be using same coins for possible combine transactions later.

For me consolidating should be done this way for privacy reasons: all little inputs on same address should be sent to one one address and this way you have just one input but do not combine inputs from other addresses to one if this re-use of address is your problem.

[Porfirii]

Thank you for sharing your knowledge with us d5000.

Since almost the beginning of my crypto-journey I have had difficulties in making decisions because of the gap between the hypothetically preferable actions and the consequences in the real world. They consist mainly in the paralysis due to the idea of creating taxable events just because of making virtual transactions.

This topic awakens the same feelings in me. If I decide to make my coins more private and secure, I can have problems in the future if I'm ever required to prove the origin of my funds. And yet, failure to follow your advice can also have negative consequences. I believe that in other jurisdictions this problem is not so common.

[dzungmobile]

Indeed, most don't know and most don't care, for the reasons you've mentioned

Don't care and don't know are two different levels of lack of information. Don't care is too more severe than don't know because if they are ready for learning, they can learn it. If they don't care, they won't learn even someone proactively teach them about these things.

plus that seeing how expensive it is to withdraw from any CEX they will use wrapped bitcoin and other altcoins.

Coins and tokens are different and people must care to learn about it first.

• Definition of tokens.

Wrapped tokens are tokens that don't have their native blockchains and they are built up on blockchains like Ethereum, Binance Smart Chain, Tron, Solana, Harmony ... They have risks that if the native blockchains on which they are deployed have technical problems, their Wrapped tokens will automatically have issues.

Wrapped Bitcoin tokens are tokens with pegs to Bitcoin price that is risky because Wrapped tokens can depeg and when a depeg event happens, rather than have 1 bitcoin, you will have 1 Wrapped Bitcoin token with value lower than 1 bitcoin or even zero.

[Patikno]

That is great advice, especially for beginners like us. For another safety reason, I always use a new wallet to secure my assets that are relatively large in value or for hodl purposes, especially in the long term, not only on Bitcoin wallets but also on other crypto wallets or altcoins. However, from your explanation, there is one thing I want to ask, does that mean we are still safe from quantum computing attacks by using a new wallet or generating a new address on the same seed phrase ?

[Btcalysis]

However, from your explanation, there is one thing I want to ask, does that mean we are still safe from quantum computing attacks by using a new wallet or generating a new address on the same seed phrase ?

Anytime you make transaction, your address public key is known already. If quantum computers is able to be used to access bitcoin private key, it will not be through bitcoin address but through the public key. If you used a bitcoin address to receiver bitcoin but you did not send the coin to another address or anyone, the public key can not be known and can not be attacked in the future with the use of the quantum computer.

So what d5000 (OP) is saying is that you should move your bitcoin to the address that you have not used to make transaction before so that your public key is not known to anyone but only you. Fees are low now which is a perfect time to transfer the coin to a new address.

[Odogwu-Blockchain]

1) Re-using Bitcoin addresses make it easier for any entity, for example chain analysis companies, but also thieves and scammers, to link your coins together. In short: Your privacy is at risk!

Then what's the need of calling it decentralization when they say, "not your keys, not your coins" a scammer doesn't have my keys and so why would I be worried about using the same address when I know for sure that nothing could happen to my balance if i receive coin in the same address.

So I got these questions;
So, whenever fees are low, it's best to always regenerate new address and send your coins to the new address?

Why doing this when fees are low and not in any regular moment?

How can my pk get exposed to this computing quantum mechanics if coins are stored in my reused address?

[NeuroticFish]

Don't care and don't know are two different levels of lack of information.

Indeed, I should have been formulating better my sentences.

Coins and tokens are different and people must care to learn about it first.

I really know the difference, just in this context I felt it doesn't matter, all are just different faces of "garbage".
But yeah, since we started teaching the newbies, it can be helpful to be correct in all terms (hence a bit of merit for ya).

[d5000]

They consist mainly in the paralysis due to the idea of creating taxable events just because of making virtual transactions.

Do you really create a taxable event in your jurisdiction when moving your own Bitcoins? If you can prove that both origin and destination addresses are yours, then normally there should be no problem.

If I decide to make my coins more private and secure, I can have problems in the future if I'm ever required to prove the origin of my funds.

I also don't understand that part. Of course, if you use mixers or similar stuff then it may be more challenging to prove the origin of your funds. But again, proving the origin of funds of a transaction you did with both keys under your own control -- something you can show to the authorities simply signing a message with both keys -- should not be a problem.

Why doing this when fees are low and not in any regular moment?

You can of course do that at any time but it's simply a convenient moment when fees are at 1-2 sat/vbyte. The problem is also not so urgent (quantum computers are far away still, at least a decade probably) that you have to hurry now with that action.

How can my pk get exposed to this computing quantum mechanics if coins are stored in my reused address?

Public keys are exposed when you spend Bitcoins. The public key of the sender is stored in every transaction, because the address is not enough to prove the correctness of the digital signature (the signature is the mechanism you prove you owned the coins on your address). As I described in the OP, if you only receive BTC but never spend them, then no action is required.

The public key could be, in the future, used to steal the Bitcoins with Shor's algorithm. This is a known problem of ECDSA, the cryptographic system used to manage public and private keys in Bitcoin. ECDSA is used in a lot of other applications (online banking and other encrypted stuff) so Bitcoin isn't the only application at risk if this becomes a problem.

But again, this may become a problem in a decade, or two, or three, or never. It's however not a bad idea to prevent that to happen already today, instead of waiting until everybody and their grandpa do it, and fees are at 1000 sat/vByte ...

[PX-Z]

[Telegram Bot] Bitcoin Fees - fees and tx tracker

Small correction of the Telegram bot ANN thread should be this one https://bitcointalk.org/index.php?topic=5445635.0
It was probably a mistake due to using a smaller screen, a mobile phone.

The direct link of the bot is here @BitcoinFeesAlert_bot

[dzungmobile]

Small correction of the Telegram bot ANN thread should be this one https://bitcointalk.org/index.php?topic=5445635.0

Thank you. I made this mistake by putting a topic ID of LoyceV's topic that was included in that post.

I really know the difference, just in this context I felt it doesn't matter, all are just different faces of "garbage".
But yeah, since we started teaching the newbies, it can be helpful to be correct in all terms (hence a bit of merit for ya).

I knew that you did knew about it, and this is for newbies who by chance read that post and have some insights to learn because I think there are not many newbies know about it while it is very helpful and even vital to keep their investment capital safely and avoid losses by wrong belief in scam tokens including Wrapped Bitcoin tokens.

[Porfirii]

They consist mainly in the paralysis due to the idea of creating taxable events just because of making virtual transactions.

Do you really create a taxable event in your jurisdiction when moving your own Bitcoins? If you can prove that both origin and destination addresses are yours, then normally there should be no problem.

No, I didn't mean that. What I said is that I haven't taken many decisions in the last years because of the fear to create taxable events, but I'm referring to trading, swapping, staking, withdraw fiat from crypto...

In the second paragraph I explained that moving funds between different accounts of mine awakens in me the same feelings, but in this case because it adds a layer of difficulty in order to prove the origins of the funds.

If I decide to make my coins more private and secure, I can have problems in the future if I'm ever required to prove the origin of my funds.

I also don't understand that part. Of course, if you use mixers or similar stuff then it may be more challenging to prove the origin of your funds. But again, proving the origin of funds of a transaction you did with both keys under your own control -- something you can show to the authorities simply signing a message with both keys -- should not be a problem.

You're right. It's just that if I'm ever asked about them, the easier the explanation the better. You never know who you will encounter and even if the explanation is very reasonable, if they want to create problems, they will. You could later prove you're right in a trial, but that's the gypsy course: "juicios tengas y los ganes".

[Patikno]

However, from your explanation, there is one thing I want to ask, does that mean we are still safe from quantum computing attacks by using a new wallet or generating a new address on the same seed phrase ?

Anytime you make transaction, your address public key is known already. If quantum computers is able to be used to access bitcoin private key, it will not be through bitcoin address but through the public key. If you used a bitcoin address to receiver bitcoin but you did not send the coin to another address or anyone, the public key can not be known and can not be attacked in the future with the use of the quantum computer.

So what d5000 (OP) is saying is that you should move your bitcoin to the address that you have not used to make transaction before so that your public key is not known to anyone but only you. Fees are low now which is a perfect time to transfer the coin to a new address.

Okay, I understand that it is recommended to use a new address and has never made a transaction. So does that mean we can use a new wallet (or generate a new address) that comes from the same seedphrase? or is it better to create a wallet from a different seedphrase? I didn't get an answer to my question, or maybe I don't understand your explanation. I hope OP or those of you who understand can also answer this, because I have little knowledge about it and really care about this security thing.

[Findingnemo]

I agree that not reusing the Bitcoin address will help with privacy and security?, too, in case quantum computing ever becomes real. But wide spreading too much can cause a burden on fees in the future because we never know how the fee situation will be. So it's better if we consolidate them once in a while to new address to tackle the fee market while also maintaining the privacy.

[Don Pedro Dinero]

Thanks for the information, d5000, most of it I already knew but the part about quantum computers I regret not having read yesterday before making a transaction to consolidate the inputs for the bet on the local forum.

The thing is that as the funds were received at an address that is published and with which I signed a message, yesterday I made a consolidation at 1.03 sats/vbyte but sent the funds to the same address. If I had thought about it I would have created a new address, transferred the funds to it, and then put it in the OP.

So, the question is: do you think it's worth taking advantage of low fee times to do this even if it means losing a few satoshis? How advanced can quantum computing be? The funds will be there until the end of the year at the latest.

[Saint-loup]

There is a special class of re-used addresses: those where you only received coins, but never spent them. This is typically the case in bounty campaigns when you decide to hodl all rewards.
It is a good idea to eventually move these coins to a fresh address too, but in this case it is best if you then never use this address again. So if you want to continue to hodl the coins which arrive in this address and not spend them, it's not necessary to move them.

What does it mean precisely? Why people would be more supposed to not spend Bitcoins earned from bounty campaigns than BTC they've bought onto an exchange, I don't get it. If you are taking part in a bounty campaign it means you are a crypto user and not just an investor, so you like using cryptos, spending them and exchanging them in my opinion.

[coinlary]

So it's better if we consolidate them once in a while to new address to tackle the fee market while also maintaining the privacy.

Yes but in some case consolidation will only bring about reduction in privacy especially when  consolidation is done on a consolidated  input to form a bigger input.
If any of this input is being tracked somehow then it will continue to expose the state of such victim portfolio.

[PrivacyG]

2) When you spend coins from an address, you expose your public key for this address and store it to the blockchain. In the future, this may enable attackers with quantum computers to compute the private key using the public key and steal your coins! [2] [3]

There's an easy fix: simply move the coins on the re-used addresses to a freshly generated address! Both Bitcoin Core and the popular SPV wallets like Electrum or Sparrow provide easy means to do that.

I never thought of the situation you present in the way you thought of it.  I know it is bad practice to reuse addresses and I have not reused an address in a LONG time anyway but I never thought of Public Keys becoming a possible target of Quantum Computers.

But I see two problems.  First of all, if no solution is found by the time an evil Quantum Computer is activated then a lot of people would start losing their Bitcoin which would in turn completely destroy the trust a lot of people had into Bitcoin.  It would lead to WAY bigger trouble than just having a reused address stolen.

Second of all, is it safe to assume that Quantum Computers able to compute a private key from a public key may be able to do much worse anyway and if Bitcoin and the internet is not ready by that time then it may be doomed?