The History of Coin
Coin is a mobile app that rewards users with digital coins for visiting local businesses. The app combines blockchain technology with location verification to create a secure and fun way for people to earn digital assets by exploring their own cities. The Coin app has partnered with the XYO foundation to prevent location spoofing – when someone pretends to be somewhere else in order to gain more coins.
Coin’s monetary value is low, but it still has substantial documentary importance. In combination with written and archaeological evidence, it yields a remarkable range of information, particularly about the wealth and power of city-states in earlier ages. Coins also contain miniature likenesses of numerous large-scale sculptural and architectural works that have been lost to history.
A coin’s value is based on the amount of metal it contains. Since coins are small, they can be easily made in large numbers and distributed widely, allowing even very poor societies to issue their own currency. This makes coins an important factor in determining global economic development.
Besides their metal content, coins often show the date of minting and may have various other inscriptions. The side of a coin bearing an image of a person or national emblem is called the obverse; the reverse, which sometimes shows historical events or legends, is known as the reverse. The space around a coin’s edge is called the exergue and may be blank, or it may contain a mint mark or privy mark.
The earliest circulating coins were made of precious metal, such as silver or gold. However, these were soon replaced by cheaper bronze and iron coins. These were usually round and carried the name of the ruler or king. Later, coins were issued with images of gods or heroes. Until the 20th century, many nations used coins made of both bronze and silver.
Today’s coins can be made of either pure silver or copper, or they can be bimetallic (combining two different metals). Coins can be produced in a variety of shapes, sizes and styles. Some are circular, while others are oval or rectangular, and some have a flat edge that is called a planche.
Some modern coins are printed with a security feature that prevents counterfeiting. This is known as an embedded security feature. This is accomplished by embedding a small microscopic pattern in the coin that is readable only with a microscope. This microscopic image is encrypted using a private key, which only the mint has access to. The coin cannot be copied or replicated, so it can’t be counterfeited.
A solution that conditionally restores forward and backward traceability into the basic cut-and-choose scheme is presented by Stadler, Piveteau, and Camenisch in [14]. In this system, the payer must commit to a deposit number at the time of withdrawal and encrypt it with a commonly trusted entity’s public key along with some other data that cannot be associated with the withdrawal. The bank then uses this deposit number to verify that the withdrawal was not tampered with.