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.
Nexus is the first truly quantum-resistant blockchain, incorporating advanced cryptography designed to negate the threat posed by quantum technology of the future. The 3DC combines 571-bit private keys, 1024-bit Skein and Keccak quantum-resistant hashing algorithms, and an evolving signature scheme called signature chains. Signature chains update the private and public keys that secure your address and obscures them after each and every transaction, maintaining the integrity and security of your account even on mobile wallets. Signature chains offer several advantages over equivalent quantum-resistant schemes such as BLISS and Lamport signatures, being extremely compact and lightweight, making it ideal for blockchain applications. The Nexus coin (NXS) is the currency of the network. There’s no cap on the amount of NXS that will be minted. Instead, the coin has a 10-year distribution period in which 78 million NXS will be distributed until September 23rd, 2024. After this time, the supply will inflate each year by a maximum of 3% through the holding channel and 1% through the prime and hashing channels. Nodes create blocks, on average, every 50 seconds, and an NXS transaction requires 6 confirmations. Currently, most transactions cost 0.01 NXS. However, once the 3DC is built and 10-year distribution is complete, transaction fees will disappear. Instead, the system will absorb the fees through inflation. Nexus didn’t hold an ICO. Instead, the project has a Developer Fund that takes a small commission from mining rewards. This commission starts at 1.5% and increases to 2.5% over 10 years. Additionally, 20% of the block rewards are slotted for marketing as well as the production and launch of the Nexus satellite network. Colin Cantrell, also known as Videlicet, is the founder and lead developer of Nexus. He first named the project Coinshield (CSD) when starting in September 2014. The original code only contained the prime channel; the team added the hash channel in October 2014. In April 2015, the team rebranded to Nexus, and they added Proof-of-Holdings in July 2015. Besides partnering with Vector on the satellite network, Nexus has also joined forces with SingularityNET to provide their 3DC architecture to the project’s decentralized AI network. Moving forward, Nexus is releasing major updates following their TAO (Tritium, Amine, Obsidian) roadmap strategy. The releases include the 3DC, mobile wallets, quantum resistance, and the satellite network, among many other things. The creation of new NXS is capped at 3 percent per year and is earned through securing the network by mining or staking. The platform is developed and maintained by the Nexus Embassy who is funded through a 1.5% commission on each block produced and from funds acquired through early mining of NXS. The commission will also gradually increase from 1.5 – 2% over the next 10 years.