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.
Zebi is a young and innovative organization founded, mentored and managed by Oxford, MIT, Stanford, and IIT veterans and thought leaders from Silicon Valley with experience in Google, Uber, Amazon, Microsoft, and Oracle. Zebi specializes in providing Blockchain based offerings to governments and enterprises to leverage and protect their high value and sensitive data. India’s big data generation is increasing exponentially and is expected to reach 3 Zebibytes per year (Zebibyte = 1024^7 bytes) by 2020, driven by continued growth of internet usage, social networks, proliferation of smartphones, as well as the digital initiatives and structural reforms undertaken by the government. At the same time, incidents of data crimes such as data hacks, data leaks, data tampering, identity thefts are on the rise, which are costing Indian organizations and consumers more than $30 billion annually. Zebi specializes in providing blockchain based solutions to governments and enterprises to leverage and protect their high value and sensitive data. Zebi is one of the few enterprise grade product companies based in India offering best of the expertise of Silicon Valley at Indian prices Recognizing the need and opportunity to enable with technology the enforcement of data protection regulations, Zebi has created a Blockchain driven, unique and holistic solution to make high value and sensitive data readily available for legitimate use. Zebi safeguards data against hacking and tampering, while obtaining consent from individuals. The solution comprises of Zebi Chain™ to provide immutability to critical records, coupled with a central hub called Zebi Data Gateway which enables secure and instant data exchange through Data-as-a-Service (DaaS) APIs. Zebi’s innovative, proprietary solution set is one of the first in industry and is patent pending.