What actually breaks in the practice?

[JiiBs]

Both of these contradicting comments can be correct.
You see the checksum size in both algorithms is very small (2-4 bits) so there can be lots of collisions. So technically an Electrum mnemonic can still be a valid BIP-39 mnemonic and vice versa. However the Electrum seed generator code added a little check in version 4.1.3 to check these cases and reject them[1]. That means if the mnemonic was generated after version 4.1.3 that little check[2] would prevent it from being a valid BIP-39 mnemonic as well so @Cookdata is correct in this case but if the mnemonic was generated before this check existed[3] there is still a chance that the Electrum mnemonic is also a valid BIP-39 one as well so @Livingleged is correct in this case!

I was a little confused on how both could be contradictory and still be correct until I read a little further on your comment.

This brings to mind the issue with the Cold Card case where, certain wallets were affected based on their seed generation pathway while others remained relatively safe.
Same comes to mind about this, since more and more upgrades brings about more sophistication in new versions.

I read somewhere that it did say, electrum wallet uses its own checksum which isn’t uniquely to BIP39 and that kind of explains it, for the version 4.1.3 as you wrote there.

[Outhue]

I wouldn't advice this, better to use each recovery seed for each crypto wallet, differently, because they all have their different security, it's possible that a recovery seed becomes less secured when you import into another wallet, you want my advice? Don't do it, better use Electrum wallet recovery seed for Electrum and use Trust wallet seed for trust wallet to avoid losses.

[eternalgloom]

I was a little confused on how both could be contradictory and still be correct until I read a little further on your comment.

This brings to mind the issue with the Cold Card case where, certain wallets were affected based on their seed generation pathway while others remained relatively safe.
Same comes to mind about this, since more and more upgrades brings about more sophistication in new versions.

I read somewhere that it did say, electrum wallet uses its own checksum which isn’t uniquely to BIP39 and that kind of explains it, for the version 4.1.3 as you wrote there.

In reality this is not possible at all.

Electrum and BIP-39 are two completely different beasts.

Their mechanisms are different.

Electrum runs on its own trademark track, its own versioning and wallet type code is hidden in its seed.

And BIP-39 is the global standard that runs on all popular wallet.

Simply put, Electrum seeds have no chance of falling through the BIP-39, they have no direct cross-connection or conversion system.

Doesn't matter what Electrum version you are on, you are gonna get slapped with checksum error every single time.

Don't trust me, verify yourself, dude.
Version archived: https://download.electrum.org/

Both of these contradicting comments can be correct.
You see the checksum size in both algorithms is very small (2-4 bits) so there can be lots of collisions. So technically an Electrum mnemonic can still be a valid BIP-39 mnemonic and vice versa. However the Electrum seed generator code added a little check in version 4.1.3 to check these cases and reject them[1]. That means if the mnemonic was generated after version 4.1.3 that little check[2] would prevent it from being a valid BIP-39 mnemonic as well so @Cookdata is correct in this case but if the mnemonic was generated before this check existed[3] there is still a chance that the Electrum mnemonic is also a valid BIP-39 one as well so @Livingleged is correct in this case!

Ahh, got worthy one to talk,,  

hi pooya87, hope you are doing well dude, nice to see you.

different addresses and zero balance basically only happen if you try to restore your SegWit seed as Legacy.

That is, if your seed is BIP-39 from another wallet to import into Electrum. Then you gotta manually set derivation path. If you mess that up Electrum generates fresh address and shows you zero balance.

If that happened just wipe it, restore again with correct wallet type to get your balance back.

But if it's any native Electrum seed then you can't even import it elsewhere(except electrum) in first place. Ending up with zero balance & address is far from coming.

[Cookdata]

Both of these contradicting comments can be correct.
You see the checksum size in both algorithms is very small (2-4 bits) so there can be lots of collisions. So technically an Electrum mnemonic can still be a valid BIP-39 mnemonic and vice versa. However the Electrum seed generator code added a little check in version 4.1.3 to check these cases and reject them[1]. That means if the mnemonic was generated after version 4.1.3 that little check[2] would prevent it from being a valid BIP-39 mnemonic as well so @Cookdata is correct in this case but if the mnemonic was generated before this check existed[3] there is still a chance that the Electrum mnemonic is also a valid BIP-39 one as well so @Livingleged is correct in this case!

Ahh, got worthy one to talk,,  

hi pooya87, hope you are doing well dude, nice to see you.

different addresses and zero balance basically only happen if you try to restore your SegWit seed as Legacy.

That is, if your seed is BIP-39 from another wallet to import into Electrum. Then you gotta manually set derivation path. If you mess that up Electrum generates fresh address and shows you zero balance.

If that happened just wipe it, restore again with correct wallet type to get your balance back.

I'm not sure if you have come across this, Electrum Wallet has this feature that helps you to "Detect Existing Accounts." Once you indicate that your seed phrase is BIP39 and import it, you can press that option, and it will help you to search different derivation paths and check which ones have activity. This helps you to detect the right one that has a balance instead of manually trying different paths to check for addresses and coin balance.

But if it's any native Electrum seed then you can't even import it elsewhere in first place. Ending up with zero balance & address is far from coming.

I think Pooya is referring to the seed, not the address and balance. He is saying that there used to be a collision of seed before version 4.1.3, which he gave an example of 12 seed phrase. I tested the seed phrase, and it's valid for both Bip39 and Electrum native, but that does not mean they produce the same address because of how Electrum create wallet types using the seed version numbers.

[snowpega]

You guys mean we can not import the Electrum wallet seed into any other wallet, because now it has its own unique one, right? CMIIW!
In recent days, I was planning to shift all funds to a decentralized wallet for long-term holding. No doubt, Electrum and Trust are both good choices for holding funds for long-term purposes, right? But in recent days, after testing Trust Wallet, I experienced that Trust Wallet sometimes delays transactions, which is surely not a good thing, right?

I am looking for the best option which is easily accessible. If anyone here replies to me about this, then please first answer my first question asked in the very first line. Thanks. The thing is, I have not used Trust and Electrum(but uses only a few times) for holding long-term funds, but since exchange incidents and frauds/hacking cases are increasing day by day i am planning to shit totally to decentralized wallets. I have also used MetaMask. Advice on this. Thanks!

[tbct_mt2]

No doubt, Electrum and Trust are both good choices for holding funds for long-term purposes, right? But in recent days, after testing Trust Wallet, I experienced that Trust Wallet sometimes delays transactions, which is surely not a good thing, right?

Electrum wallet is a good choice.
Trust wallet is not a good one.
The first one is open source, the second one is close source.

Delay transactions, is it an issue from blockchain or from Trust wallet, you must confirm this information clearly.
Trust wallet and Electrum wallet are both not responsible for any congestion in Bitcoin mempools and Bitcoin blockchain.

You will need to check Bitcoin mempools and use good fee rates for your transactions to have a first quick confirmation.
https://jochen-hoenicke.de/queue/#BTC%20(default%20mempool),24h,weight

[snowpega]

Electrum wallet is a good choice.
Trust wallet is not a good one.
The first one is open source, the second one is close source.

Delay transactions, is it an issue from blockchain or from Trust wallet, you must confirm this information clearly.
Trust wallet and Electrum wallet are both not responsible for any congestion in Bitcoin mempools and Bitcoin blockchain.

You will need to check Bitcoin mempools and use good fee rates for your transactions to have a first quick confirmation.
https://jochen-hoenicke.de/queue/#BTC%20(default%20mempool),24h,weight

Thanks for the quick reply, but the answer to my first question is still pending.
Maybe the other users will tell me about this. Other than that, regarding the transaction delays with Trust Wallet, I confirmed with another user that he also dislikes this issue with Trust Wallet. I think the chances are higher that this is an issue with Trust Wallet that delays the transaction. As I use other sources, my transactions never delay or take more time to be completed. This is why I discuss this matter here. So, in case any member is using Trust Wallet for long-term holding, can indicate me on this.

Electrum sounds like a good choice also because it is an open-source platform. Well, I will try to do my best research before picking any of them.

[Stalker22]

You guys mean we can not import the Electrum wallet seed into any other wallet, because now it has its own unique one, right? CMIIW!

You can import it into other wallets, but you have to select the Electrum seed type or derivation path during setup.  Wallets like Sparrow or Bluewallet support it directly.  Alternatively, you will always have the option to import individual private keys from Electrum into other wallets.

But why does that matter when choosing your next wallet?  If you decide to use Electrum, stick with it.  Importing seed phrases between different software is generally bad practice for security reasons.

In recent days, I was planning to shift all funds to a decentralized wallet for long-term holding.

"Decentralized wallet" is an incorrect term here.  Wallets dont hold your funds - the blockchain does.  You are looking for a self-custody wallet, where you hold the keys instead of an exchange.  Exchanges can be centralized (CEXs) or decentralized (DEXs), but there is no such thing as a decentralized wallet.

[taufik123]

-snip-
Delay transactions, is it an issue from blockchain or from Trust wallet, you must confirm this information clearly.
Trust wallet and Electrum wallet are both not responsible for any congestion in Bitcoin mempools and Bitcoin blockchain.

You will need to check Bitcoin mempools and use good fee rates for your transactions to have a first quick confirmation.
https://jochen-hoenicke.de/queue/#BTC%20(default%20mempool),24h,weight

Transaction delays are only caused by the Bitcoin network being too congested, which is not entirely due to the type of wallet used.
And the use of cost rates also needs to be adjusted, because an increase in costs will always occur.
A few weeks ago my Bitcoin transaction was stuck for up to 4 hours more due to the Bitcoin network being too congested.

[NotATether]

But why does that matter when choosing your next wallet?  If you decide to use Electrum, stick with it.  Importing seed phrases between different software is generally bad practice for security reasons.

Where did you hear that it's a bad security practice? As far as I know, only downloading and running an untrusted wallet software is bad practice (including security updates).

Restoring your seed phrase somewhere cannot harm you unless a keylogger or stealer is running.

[nc50lc]

Simply put, Electrum seeds have no chance of falling through the BIP-39, they have no direct cross-connection or conversion system.

Doesn't matter what Electrum version you are on, you are gonna get slapped with checksum error every single time.

It's not about connection or lacking of conversion of the two standards, it's because the two share the same word list.
(note: Electrum isn't constrained by a fixed word list by design but it uses BIP39's word list by default)

So in actual reality, a 12-word combination generated by Electrum can have a correct checksum bytes of a BIP39 seed since its 4 bits size isn't even that reliable. (2^4 or an average of 1/16 chance)
That's the reason why Electrum devs added this in 4.1.3: https://github.com/spesmilo/electrum/blob/master/electrum/mnemonic.py#L227-L231

Here's how Electrum generates its seed phrase:

• From its randomly generated entropy, it encodes it into a mnemonic: github.com/spesmilo/electrum/blob/master/electrum/mnemonic.py#L178-L185 where i = entropy + nonce (starts at zero)
  But that's just one candidate seed phrase.
• After that, it checks if it matches the "old_seed" type or has a valid BIP39 checksum, if it does, it continues back to generate a new candidate by adding +1 to the nonce appended to the entropy.
  Ref: github.com/spesmilo/electrum/blob/master/electrum/mnemonic.py#L219-L231
• Then if it's neither of the two, it checks if it's a is_new_seed by matching the version_number intended for the target script type (SegWit by default)
  Ref: github.com/spesmilo/electrum/blob/master/electrum/mnemonic.py#L232-L233
• If not, back to adding +1 to the nonce until it satisfies all those conditions.

So without the check added in v4.1.3, those that have a valid BIP39 checksum wont be filtered out
And if it also produces the correct version_number, it'll be presented to the user even if it's both valid Electrum and BIP39 seed like pooya's example.

Here's one example of the confusion that pre v4.1.3 caused: Same seeds on the Electrum and Mycelium Wallet - Problem?
Posted only a few weeks before that update, OP must have been using an older version (I've read a few more but can't find them)

[JiiBs]

Simply put, Electrum seeds have no chance of falling through the BIP-39, they have no direct cross-connection or conversion system.

Doesn't matter what Electrum version you are on, you are gonna get slapped with checksum error every single time.

Sorry but, I’ve got to ask this

With BIP-39 being the global standard that runs on all popular wallets like you’ve said and Electrum being one popular wallet as well,

If the Electrum seed has no chance of falling through BIP-39, what explains the checksum error every single time?
Would that be the trademark it runs on due to the code hidden in its seed?

Would this be correct as it concerns what you are trying to explain above or am I mixing something up here.

Just pull me through on these:

Simply put, Electrum seeds have no chance of falling through the BIP-39, they have no direct cross-connection or conversion system.

Doesn't matter what Electrum version you are on, you are gonna get slapped with checksum error every single time.

[Georgethompsonn]

Wouldn’t it be easier to just make a new wallet and send the BTC there? Importing seeds between wallets seems like more trouble than it’s worth.

[Stalker22]

But why does that matter when choosing your next wallet?  If you decide to use Electrum, stick with it.  Importing seed phrases between different software is generally bad practice for security reasons.

Where did you hear that it's a bad security practice? As far as I know, only downloading and running an untrusted wallet software is bad practice (including security updates).

Restoring your seed phrase somewhere cannot harm you unless a keylogger or stealer is running.

The general consensus in the security community is to minimize exposure.  You are right that the biggest, most obvious danger is running malicious or untrusted wallet software.  But every time you type a seed phrase into a new device or application, you are exposing those secrets to a fresh set of potential vulnerabilities.

My thinking is that the use of a single, trusted wallet (or better yet, a hardware wallet where the seed phrase never touches an OS running an internet-connected device) keeps your risk exposure minimal and predictable.

[JiiBs]

Wouldn’t it be easier to just make a new wallet and send the BTC there? Importing seeds between wallets seems like more trouble than it’s worth.

There are several reasons why someone might need to import their wallet into a device, some of them includes;
1. Cases of lost device containing your wallet
2. The need to have your wallet on more than one device
3. Cases where a particular wallet version might not be available for mobile/desktop/laptop or on Android/iOS
4. To serve a users particular need(s).

All these and more could be some of the reason for wallet importation.

When you haven’t got the wallet on your device and the seed is lost, then there would be nothing to send. If you’ve got the seed, then you can always import and have access to your coin.

The subject here though is an attempt to understand how seed importation works between different wallets.

[snowpega]

You can import it into other wallets, but you have to select the Electrum seed type or derivation path during setup.  Wallets like Sparrow or Bluewallet support it directly.  Alternatively, you will always have the option to import individual private keys from Electrum into other wallets.

What do you mean here by individual private keys? Do you mean I can be able to fetch the desired pattern of keys using Electrum according to the wallet which I am going to use, or can Electrum give us that pattern of PV, right? CMIIW!

But why does that matter when choosing your next wallet?  If you decide to use Electrum, stick with it.  Importing seed phrases between different software is generally bad practice for security reasons.

This is so obvious, which I am also aware of. Connecting or importing a private wallet in unnecessary places or random places is a very stupid practice indeed. I was asking because sometimes you really need to import your wallet in other safe places. So that I can easily access my funds using another secure wallet too (but this is just an in-case scenario).

"Decentralized wallet" is an incorrect term here.  Wallets dont hold your funds - the blockchain does.  You are looking for a self-custody wallet, where you hold the keys instead of an exchange.  Exchanges can be centralized (CEXs) or decentralized (DEXs), but there is no such thing as a decentralized wallet.

Oh yes, I literally said wrong and really knew about this because this is also the difference between DEX and CEX. Link: while using a CEX, we don't have a private key, and our funds stay under third-party custody. But in terms of a wallet, we have all that, which is enough to give us full direct access to our funds. Thanks for reminding me of this, haha.

[Stalker22]

You can import it into other wallets, but you have to select the Electrum seed type or derivation path during setup.  Wallets like Sparrow or Bluewallet support it directly.  Alternatively, you will always have the option to import individual private keys from Electrum into other wallets.

What do you mean here by individual private keys? Do you mean I can be able to fetch the desired pattern of keys using Electrum according to the wallet which I am going to use, or can Electrum give us that pattern of PV, right? CMIIW!

What I mean  is that instead of importing the seed phrase, you can use Electrum to export the key pairs for all generated addresses and use them to import into another wallet.
You just need to go to Wallet -> Private keys -> Export.  Alternatively, you can open the "Addresses" tab and select "Private key" from the right-click menu for a specific address.

"Decentralized wallet" is an incorrect term here.  Wallets dont hold your funds - the blockchain does.  You are looking for a self-custody wallet, where you hold the keys instead of an exchange.  Exchanges can be centralized (CEXs) or decentralized (DEXs), but there is no such thing as a decentralized wallet.

Oh yes, I literally said wrong and really knew about this because this is also the difference between DEX and CEX. Link: while using a CEX, we don't have a private key, and our funds stay under third-party custody. But in terms of a wallet, we have all that, which is enough to give us full direct access to our funds. Thanks for reminding me of this, haha.

It is common to use the terms "custodial" and "non-custodial" (or "self-custody"). 
Custodial: A third-party company (such as a crypto exchange or bank) holds your private keys and manages security for you.
Non-custodial (Self-custody): You hold your own private keys and recovery seed phrase.