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.
Gnosis is a prediction market platform built as a decentralized application (dapp) on the Ethereum network. The platform includes a multisig wallet as well as a Dutch Exchange, but we’re just going to focus on their flagship product, the prediction market, for this guide. More than just building a prediction market, though, Gnosis is creating an entire infrastructure layer that you can use to build your own prediction market app. A prediction market utilizes user predictions to aggregate information about future events. Users in the market trade tokens that represent the outcome of a certain event. Because some outcomes are more likely to occur than others, these tokens end up having different values in the open market.Olympia is Gnosis’s test version of their prediction market app. They host free tournaments in this product, so you get a chance to try it out without having to spend money. Every two days, the team allocates you a certain amount of Olympia (OLY) tokens that you use to bet on different prediction markets. If you do well in the market, you win Gnosis (GNO) tokens. You can sell GNO on the open market which gives them some monetary value. The next phase of Gnosis is its Management Interface. The team released a beta version in December 2017 but haven’t announced a date for the main net release. The Management Interface is basically your dashboard for Gnosis’s prediction markets. It’s here that you check your balance, participate in markets, and even create your own market. Gnosis includes two types of tokens: Gnosis (GNO) and OWL. GNO are the ERC20 tokens that the team sold during their ICO. They created 10 million GNO tokens and aren’t minting any additional ones. These are the tokens that you see being traded on the open market. By staking GNO, you receive OWL tokens. To do this, you must lock your GNO in a smart contract making them non-transferable. The amount of OWL you receive is dependent on the length of your lock period as well as the total supply of OWL tokens in the market. The team is aiming to have 20x more total OWL than the average amount of monthly OWL usage over the previous 3 months. The Gnosis team is led by Martin Köppelmann (CEO), Stefan George (CTO), and Dr. Friederike Ernst (COO). Köppelmann and George began working on the platform in January 2015 as one of the first ConsenSys partners. By August of that same year, they launched the alpha product as the first major dapp on Ethereum. In April 2017, the project held somewhat of a controversial Initial Coin Offering (ICO). Using a dutch auction style of raising funds, the team hit their $12.5 million hard cap in ten minutes while retaining 95% of the tokens. Amidst backlash, the team locked the tokens in a vault and have promised not to dump them on the market. They’ll give at least a three-month warning before selling any of the tokens. The team includes quite a list of reputable advisors including Joseph Lubin (Ethereum co-founder and ConsenSys founder) and Vitalik Buterin (Ethereum founder and chief scientist).