The bitcoin network is a peer-to-peer payment network that operates on a cryptographic protocol. Users send and receive bitcoins, the units of currency, by broadcasting digitally signed messages to the network using bitcoin cryptocurrency wallet software. Transactions are recorded into a distributed, replicated public database known as the blockchain, with consensus achieved by a proof-of-work system called mining. Satoshi Nakamoto, the designer of bitcoin claimed that design and coding of bitcoin began in 2007. The project was released in 2009 as open source software. The network requires the minimal structure to share transactions. An ad hoc decentralized network of volunteers is sufficient. Messages are broadcast on a best effort basis, and nodes can leave and rejoin the network at will. Upon reconnection, a node downloads and verifies new blocks from other nodes to complete its local copy of the blockchain. A bitcoin is defined by a sequence of digitally signed transactions that began with the bitcoin's creation, as a block reward. The owner of a bitcoin transfers it by digitally signing it over to the next owner using a bitcoin transaction, much like endorsing a traditional bank check. A payee can examine each previous transaction to verify the chain of ownership. Unlike traditional check endorsements, bitcoin transactions are irreversible, which eliminates the risk of chargeback fraud. Although it is possible to handle bitcoins individually, it would be unwieldy to require a separate transaction for every bitcoin in a transaction. Transactions are therefore allowed to contain multiple inputs and outputs, allowing bitcoins to be split and combined. Common transactions will have either a single input from a larger previous transaction or multiple inputs combining smaller amounts, and one or two outputs: one for the payment, and one returning the change, if any, to the sender. Any difference between the total input and output amounts of a transaction goes to miners as a transaction fee. In 2013, Mark Gimein estimated electricity consumption to be about 40.9 megawatts (982 megawatt-hours a day). In 2014, Hass McCook estimated 80.7 megawatts (80,666 kW). As of 2015, The Economist estimated that even if all miners used modern facilities, the combined electricity consumption would be 166.7 megawatts (1.46 terawatt-hours per year). To lower the costs, bitcoin miners have set up in places like Iceland where geothermal energy is cheap and cooling Arctic air is free. Chinese bitcoin miners are known to use hydroelectric power in Tibet to reduce electricity costs. Various potential attacks on the bitcoin network and its use as a payment system, real or theoretical, have been considered. The bitcoin protocol includes several features that protect it against some of those attacks, such as unauthorized spending, double spending, forging bitcoins, and tampering with the blockchain. Other attacks, such as theft of private keys, require due care by users.
Gulden is a second-generation peer-to-peer cryptocurrency which was created to provide a secure, simple and fast method of performing financial transactions between private individuals, customers & service providers and also corporate entities. Like many recent cryptocurrencies, the primary design criteria were to improve the security and usability of the currency and its underlying transaction authorisation technology (when compared to the original cryptocurrency - Bitcoin). The purpose of these changes was to simplify use and increase its adoption as a convenient, cheap and safe form of payment. The original initiative for this currency came from Rijk Plasman with the first working implementation released on the 4th April 2014. Initially called the “Gulden coin”, this was subsequently abbreviated in October 2015 to “Gulden”. The name Gulden comes from the German and Dutch term for “gold coin” and is the Dutch name of the Dutch guilder, the pre-euro currency of the Netherlands. Gulden Coin is the currency that enables the user to pay safely, conveniently and quickly. Moreover, it is a lucrative investment opportunity at the moment, considering that since entering the market in 2016 the developers have increased to a market capital of 39,883,259 USD with about 800,000 USD. The model of making cryptocurrencies accessible to ordinary consumers in the future holds enormous potential in the fintech sector.