Bitcoin (BTC) is a peer-to-peer cryptocurrency that aims to function as a medium of exchange independent of any central authority. BTC can be transferred electronically in a secure, verifiable, and immutable manner.
Launched in 2009, BTC is the first virtual currency to solve the double-spending problem by timestamping transactions before broadcasting them to all nodes in the Bitcoin network. The Bitcoin Protocol provided a solution to the Byzantine Generals Problem with a blockchain network structure, an idea first created by Stuart Haber and W. Scott Stornetta in 1991.
The Bitcoin whitepaper was published under a pseudonym in 2008 by an individual or group using the pseudonym "Satoshi Nakamoto", whose underlying identity has yet to be verified.
The Bitcoin protocol uses a Proof-of-Work (PoW) algorithm based on SHA-256d to achieve network consensus. Its network has a target block time of 10 minutes and a maximum supply of 21 million tokens, with a decreasing token issuance rate. To avoid fluctuations in block time, the network's block difficulty is adjusted through an algorithm based on the block times of the previous 2016 blocks.
With a block size limit of 1 megabyte, the Bitcoin Protocol supports both the Lightning Network, a layer-2 infrastructure for payment channels, and Segregated Witness, a soft fork to increase the number of transactions in a block, as solutions for network scalability.
