Do all consensus algorithms aim to solve the Byzantine generals problem?

Can I clarify my understanding:

Byzantine Fault Tolerance is a characteristic of a system to tolerate a class of failures belonging to the byzantine generals problem.

Byzantine Fault tolerance is also the name of the consensus algorithm that solves the byzantine generals problem?

I see Ripple as being BFT. Does it mean it uses some custom algorithm, that solves BFT?

I also see Stellar uses BFT, does this mean that Stellar and Ripple Both use different algorithms that solve BFT?

Edit:

Can all Proof of Insert word algorithms be seen to be a part of BFT? Because POW uses a probabilistic model to solve the generals problem, but it is not seen as BFT.

Bitcoin multisig contract – to Lock coins with nTimeLock (BIP65)

I really need help.
I am currently Developing a Bitcoin wallet and want to build in a SMS Based send function where the sender does not need to know the receiver publicKey. After the contract get executed on the reciever phone through the wallet the public key should be added to it and execute the redeem process / script.

Is that possible in any way?

Buy Order to Exchange

I am looking for a tool with which to place a purchase order which is higher than the current price.

As an an example.

Wallet Exchange: $ 100
Course NEO: 50 dollars

Order: Buy at $ 54

Does anyone have an idea how to do something like this?

Where can I get a visual example of the entire bitcoin network starting from physical network to the overlay network

*Note I am not a technical person so excuse any misunderstandings on my part here.

I am looking to get a sense of how the entire system looks like as a whole starting from the physical hardware (such as miners and full nodes) to overlaying networks (node transaction relays maybe?) to mobile clients omitting and receiving transaction data.

What prevents anyone from spending utxos from a native segwit address?

I read that transactions spending utxos from a native segwit address ( an address starting with bc1) are seen as anyone can spend transactions by legacy nodes.

So what prevents someone from taking a utxo from a native segwit address and using it to fund a transaction with a scriptsig of OP_TRUE or null ,and submitting it to a legacy node or directly to a miner?

Cryptomining in Games

Following the press last months, you could read articles about cryptomining via javascript. Basically, you open a web page, and a villiant person/company/organisation put some code in website which uses your computers or mobile phone cpu to mine various crypto currency. At the first look, this doesn’t look very effective, but the one using this approach is

  • distributing the (possible small) processor load over many clients, and
  • does not need to pay the energy needed for mining

The problem with this approach is, that the user could detect this cpu-hijacking pretty easily, either by a high cpu load or a rapidly fast decreasing battery. Plus, many users tend to use an adblocker or similar things to avoid this.

Thinking the whole thing one step furter: How to keep people from recognizing this? Assume you play the newest 3D shooter, you expect your cpu to be at high load. So what would prevent a software studio from putting some mining algorithm into the game’s source code? No one would ever notice.

So the question is: Is there a theoretical or even pratical way to prevent this? Are there any games which are known doing this?

Setting up Bitcoin Core Wallet

Trying to set up Bitcoin Core Wallet.

I’ve started blockchain synchronization 4 times and each time it has reached a certain percentage and then failed. I’ve followed instructions on the website, tried running it in pruned mode, tried running it with reindex. Is anyone else facing the same problem?

Worse still, it restarts downloading every block after it fails. Any ideas? Is there a way to force a restart at a location. This is very frustrating. And have to say this is poor quality software. Bitcoin has no future if just setting up a full wallet is so difficult.

Debug.log

Why sending bitcoin and one addresss shows (Unspend) and one address shows (Spent)?

I sent some btc to a btc address, and each time we send btc, it gets to split into two addresses, only one of them is the real destination address. The recipient said he has not received the the btc yet. I checked blockchain info, it shows the detination address (spent) but the other address as (unspent). This is normal right? If the recipient’s wallet address shows spent, it means the btc has arrived in his wallet right?

Please confirm. Thanks!

Does every miner verify blocks that are already in the Blockchain [duplicate]

Once a miner adds a block to the chain, does every other miner have to check that block to make sure that its transactions don’t violate any rules?

For instance, if a miner added a block with an invalid transaction, is every other miner expected to check that block (and perhaps compare each transaction in it with every other transaction in every other block, to prevent, say, double spending)?