Governments will never use bitcoin as their national currency.
Why should they give up all of their control? They have the ultimate power. Printing money like bitfinex prints tether.
That would be nutty of them.

Additionally i don't agree with the assertion of bitcoin not having any value comparable to fiat.

Bitcoin brings the value of a free trustless system, which allows you to transfer wealth over the internet in no time. This is not achievable with any centralised system.
Not having to trust a 3rd party and still enjoying all the benefits from transfer speed and security is definetely something which brings bitcoin a lot of value.

Unfotunately there is no real solution to your problem.

But you could prevent this from happening in the future.
You might consider using a mixing service. ChipMixer allows you to split/merge into smaller/bigger units of BTC and export these private keys.
This way you will have different amounts of BTC's sitting on your addresses.
This will prevent anyone to see how much you really own, assuming you don't mix all of those UTXO's together in one transaction afterwards.

One disadvantage would probably the high performance on ASIC's [1] which would lead to a more centralized system.
There is no need to switch to SHA-3.


Statement from NIST:
Source: https://csrc.nist.gov/projects/hash-functions/nist-policy-on-hash-functions




[1] https://ehash.iaik.tugraz.at/wiki/SHA-3_Hardware_Implementations#High-Speed_Implementations_.28ASIC.29

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No. Hash functions are also used for verification.
Probably the simpliest example: Checksums [2] (e.g. Message Authentication Code (MAC)).

In Bitcoin a hashing function allows to easily verify all transactions within a block.

And additionally it serves as PoW.



[2] https://en.wikipedia.org/wiki/Checksum

Wow. You didn't even read the first reply in this thread?
It is stated, that it is currently not possible to sign messages from P2SH addresses (starting with 3..).

If you are interested in the reason why its currently not possible, you can read the replys to this post: https://github.com/bitcoin/bitcoin/issues/10542

The private key is used to derive the public key, to sign transactions/messages and prove the ownership of the corresponding public key.




The private key itself is not 'stored inside' the transaction. But it is used to create a valid signature which basically says: 'I want to spend the UTXO from this public key'.
A valid signature can only be created with the private key corresponding to this public key. This signature can then be verified with the public key.
Miners do validate the transaction before including it into a block. After a block containing this transaction has been added to the blockchain,
every full node does validate the whole block for itself. This prevents miner from adding transactions with an invalid signature into a block.

A wallet is basically a piece of software which manages your private-/public keypairs.
Most wallets are Hierarchical Deterministic wallets. Those derive a new private key from a so called master private key (MKP).

Upon encrypting (or changing password of) your wallet.dat, core generates a new MPK.
Any generated address after this will onle be cointained in this version of your wallet.dat + futures backups, not in older ones.

Therefore if you (or the second person who has a copy of yor wallet file) spend(s) a part of the coins, the change of the transaction goes to a change address which has only been generated by the wallet the transaction came from.
The actual amount of coins not being 'available anymore' in the older version depends on the UTXO's which have been included into the transaction.

It is not the segwit 'implementations' who cause a failure when signing/verifying messages.

You can't verify messages signed with with P2SH addresses since you can't know whether the public key corresponds to a nested p2wpkh address.
You can't be sure what p2sh address it would correspond to, since a public key can be a part of multiple ps2sh addresses.

With a p2pkh address, on the other hand, the public key only corresponds to one p2pkh address.

How much will be accessable from the other copy of the wallet.dat depends on how much UTXO's are available.
After one user encrypts the wallet (new seed / addreses being generated afterwards), the next transaction from this user will have
an output (change address) which the other user doesn't have control of.

If there is only one UTXO, the figure will be like shown by ranochigo.

Depending on how much UTXO's are used in the transaction, the amount of 'remaining btcs' for the first user to spend is varying.



For more information about the change: https://en.bitcoin.it/wiki/Change

To make this more clear:

While the risk when using the same address multiple times is slightly higher (due to the revealed public key), this can be neglected.
The real advantage when using change addresses is the privacy factor you gain.
It makes it harder to trace your payments and increases your level of anonymity.

You may also check wether your electrum version is the original one before loading up more funds.
You can either check the signature (best way of verifying the file) (small guide: https://steemit.com/bitcoin/@jklepatch/how-to-verify-the-integrity-of-electrum-wallet-executable-on-windows).
Or you go the fast way and simply compare the hashes.

Assuming you are in windows, you can use this command (on command line) to hash your executable:


SHA256-Hash of electrum-3.1.2-setup.exe:
ab82319dff3bef0604fe173d45d94e3ede7dc3947d41ce59976a0b07c0357c71

SHA256-Hash of electrum-3.1.2-portable.exe:
ef64c35821c86d94ba11e075405e34c60d3f8992c59f2ca3024f52748f26fc55

Mining on a mobile does not have 'to be supported'.
Neither do you need a wallet on your mobile to mine cryptos.

All you need is a small application which uses the mobiles processor to make the POW.




They can definetely be mined on a mobile. But depending on the hashrate a mobile phone is able to achieve, this whole process is kind of senseless.
But mining itself is possible on a mobile. In the end, mining is just a 'specific way of calculations' (which any processor can do).




For PoS mining, your funds have to be staked. This can be done from any device where you can access your wallet and the internet.
Mining software != wallet

Segwit nested into P2SH was thought as a way of transition from legacy to segwit (bech32).
While nested segwit does reduce the transaction weight, it is still not as efficient as bech32.

Changing user habits is a tedious process. Moving from legacy to nested segwit is definetely a step in the right direction.
But the goal should be to get widespread bech32 adoption. It doesn't just improve the user experience, but also contributes to the overall network health.


@OP:
Is there a particular reason you want to use an legacy addresse?
General rejection towards segwit?

While 65535 bytes is the theoretical maximum for a 'tcp packet', which by the way is stream based (why do you care about packet size when using TCP?),
lower layers are not able to process such big packets without errors.

In the end a single packet sent over a tcp connection is always lower than those 65535 byte.

While a hardware wallet is not 100% secured (nothing is 100% secured) it is definetely better than an online wallet.
The attack surface of a web wallet is by far bigger than the attack surface of a hardware wallet.

The point is: If you decide to stop using your hardware wallet and put it in a safe place.. your coins are safe. Regardless of a vulnerability.
But a web wallet on the other hand can be attacked 24/7. Not that you just have to trust the developer of the wallet, you also have to trust they
are able to secure their whole infrastructure good enough.

While hardware wallets may not be the most secured storage option, it definetely can be regarded as more secured than an online wallet.

Hardware wallets which use a secure element (e.g. ledger nano s) are not completely open source.
This is simply due to the fact that those chips are mostly available to developer/manufacturer only.

Most of the hardware is under CDA. Ledger simply is not allowed to disclose how they interact with the element.

The majority of the source code is on github. But unfortunately not completely.

Unfortunately there are way to less mobile apps for windows or iOS.
It is possible to run android apps on a windows phone. But this requires to connect the phone with your PC in debugging mode
and access/modify the firmware. Then you could simply copy an android .apk onto your phone and install it.

However, this is not recommended since messing with the firmware of your phone might cause some damage when not being careful.

I'd like to introduce you at least one entity with a) massive power and b) tons of money in this unregulated market which never
would BTC fall that low again: Miners.

It just doesn't make any sense to me for miners NOT to push the price up while sitting on huge stacks of BTC's.
Its not like its not possible to push the price up successfully. The market reacts highly volatile. Manipulation is way easier than in a regulated market.

So until you can explain to me why miner should sit on ther BTC's and watching the value to drop instead of 'investing' a small portion into a pump
to overall increase their $ value, i'd label your post as FUD.

With wallet you are referring to the password manager file, right?




In a perfect world (where you password manger doesn't have a vulnerability (and never will have) and the encryption is chosen ight), yes. It is safe.
The problem is.. once you are uploading it.. it may be (somehow) read  / accessed by an attacker (who at this time can't read it because its encrypted).
But if in the future someday a vulnerability would be found (e.g. encryption algorithm implemented wrong), then he may be able to access your file, abusing the flawed implementation.




If its not encrypted, this is possible. Either by Man-in-the-Middle attacks or through accessing the server of your storage provider.
Storing/sending files unencrypted can definetly lead to a loss of your funds.




The probability of an attacker accessing your file + vulnerability found and used itself is pretty low.
But this can't be excluded.
This all depends on how much you trust the devs from your password manager and of course the 'level' of security you want to reach.

While this may work well in most cases.. the risk still exists.

There are several possibilities to implement it.
You can either use a 3rd party service to process the payments or you do it yourself.

An example: Once a customer decides to buy an article, you request a new address from your local daemon (or take one unused pregenerated address)
and assign it to your customer in your database.
Then you display the QR and after the (correct) transaction has been received by your node and has the amnount of confirmation you decided to set,
you can afterwards release the digital item to your customer.

Im not sure 'how behind the scene' you are asking for.
But there are a lot of code snippets available on github which can deliver you an technical insight.

I think HCP already explained it pretty well.

For another small explanation visit this site: https://bitcoin.org/en/how-it-works.
A slightly more detailed conclusion: https://coinsutra.com/bitcoin-private-key/.

Or, probably one of the best sources (if not the best), the original Whitepaper by Satoshi.