27GB as of 2020-06-14
You yourself can check this via going to .bitcoin/blocks/index folder. Where .bitcoin folder is usually hidden folder on home when using linux.
It depends if you have pruned than the index folder might appear less in size. As of today my index folder is 105.4 MB since I've prune=1000 and it would remain the same in future as well.
I want to store one bitcoin in my pendrive and how much free space do I need to store that information?
TL;DR: 32 bytes.
Bitcoins are not pieces of data, Bitcoin is a unit of measure.
To store any amount of Bitcoin in a pendrive you just store a private-key on the pendrive. That is a 256-bit number. It is exactly the same size for 0 Bitcoin, 0.00001 ...
Why don't we force miners to embed the height of the TX Merkle tree in the first two bytes of the 4-byte block header version?
That would be a sane softfork, but it would need to take into account that due to BIP65, the block version (which is a signed integer) needs to be at least 4, restricting it to 2^31-4 values. Maintaining compatibility with BIP9 and ...
I have seen people say that you just need the private key and "some software" to recover your bitcoin. What does this actually mean in the real world? Can someone give an example?
What it means is that your funds are secured cryptographically, and not on a server somewhere.
If you lose your private key(s) there's no customer service rep that can ...
If the computer that stores the bitcoin is destroyed, how does someone access their bitcoin?
Buy a new computer, download and install almost any wallet program, then either restore a backup of their wallet data file or key in their secret number or key in a phrase of typically 12 or 24 words that is turned into their secret number.
I have seen people say ...
When Alice pays Bob, she creates a Bitcoin transaction. Her payment to Bob is defined in an output of the transaction. This output is encumbered with a cryptographic challenge tied to Bob's public key. You can think of this as the funds getting stored in a lockbox addressed to Bob. When Alice's transaction gets confirmed, it gets recorded in the Bitcoin ...
where is the actual data stored?
Each full node on the network will download and validate the blockchain history, it will request and receive this data from other full node peers. Each node does not necessarily have to keep that data after validating it though, it can choose to 'prune' data that is not relevant to the user's wallet.
For e.g. bitcoin as of ...
Yes, it's the whole block. The hex text is 2.5 MB. Hex has 50% efficiency, so the block is 1.25 MB.
Since SegWit, blocks can be larger than 1 MB. There's a 4 MB hard limit which is almost impossible to reach. (With the largest block to date being 2.4 MB, 4.8 MB in hex)
No they are not stored, the child keys are calculated from the master when needed as they are deterministic, not random.
Here are some references: