Research bitcoin software

[sjinko]

Annotations from “Bitcoin". Wikipedia.org. Nov. 28, 2021: https://en.wikipedia.org/wiki/Bitcoin.

Units for smaller amounts of bitcoin are the milibitcoin (mBTC), equal to 1/1000 bitcoin, and the satoshi (sat), which is the smallest possible division [...] representing 1/100 000 000 bitcoin.

The bitcoin blockchain is a public ledger that records bitcoing transations [where] each block contain[s] a hash of the previous block up to the genesis block. A netork of communicating nodes running bitcoin software maintains the blockchain. [...] nodes can validate transactions, add them to their copy of the ledger, and then broadcast these ledger additions to other nodes. To achieve independent verification of the chain ownership each network node stores its copy of the blockchain.

The storing of the copy of the blockchain by each node takes too much energy.

Data structure of the blocks in the ledger (Wander):
https://en.wikipedia.org/wiki/Bitcoin#/media/File:Bitcoin_Block_Data.png

Transactions are defined using a Forth-like scripting language. [...] To prevent double spending, each input must refer to a previoius unspent ouput in the blockchain. [...] Since transactions can have multiple outputs, users can send bitcoins to multiple recipients in one transaction. [...] Any input satoshis not accounted for in the transaction outputs become the transaction fee.

The blocks in the blockchain were originally limited to 32 megabytes in size. [...] Eventually the block size limit of one megabyte created problems for transaction processing, such as increasing transaction fees and delayed processing of transactions. Andreas Antonopoulos has stated Lightning Network is a potential scalling solution and referred to lightning as a second routing network.

To be able to send their bitcoins, the owner must know the corresponding priate key and digitally sign the transaction. The network verifies the signature using the public key.

Regarding ownership distribution, as of 16 March 2018, 0.5% of bitcoin wallets own 87% of all bitcoins ever nminded.

This concentration of capital seems higher than in traditional banking system (to be checked). In any case, this is far of a fair distribution of ownership.

Miners keep the blockchain consistent, complete and unalterable by repeatedly grouping newly broadcast transactions into a block, which is then broadcast to the network and verified by recipient nodes. Each block contains a SHA-256 cryptographic hash of the previous block, thus linking it to previous block and giving the blokchain its name. To be accepted by the rest of the network, a new block must contain a proof-of-work (PoW). The PoW requires miners to find a number called a nonce (number used once), such that when the block content is hashed along with the nonce, the result is smaller than the network’s difficulty target. [...] By adjusting this difficulty target, the amount of work needed to generate a block can be changed. [...] As of September 2021, it takes on average 79 sextilion attempts to generate a block hash smaller than the difficulty target.

This increasing difficulty to achieve mining limits the capacity of any individual to participate in the process, thus restricting mining activities to individuals or organizations equiped with necessary computing power.

As of 2013 just six mining pools controlled 75% of overall bitcoin hashing power. [...] Around the year 2017, over 70% of the hashing power and 90% of transactions were operating from China.

Bitcoin does not only concentrate capital to groups of individuals, but to nation-states as well, reinforcing the forms of inequalities it generates.