Developer Things

Senior advisor for digital assets at the United States Securities and Exchanges Commission (SEC) Valerie Szczepanik reportedly noted that stablecoins could experience issues under current securities laws. Blockchain-related news website Decrypt  reported  her comments on March 16. Szczepanik, also known as the Crypto Czar, was appointed to the new position of associate director of the Division of Corporation Finance and senior advisor for Digital Assets and Innovation for Division Director Bill Hinman in June of 2018. When Szczepanik reportedly made the statement concerning securities at Austin’s SXSW conference on March 15, she also broke stablecoins into three categories. One kind of stablecoins are the ones tied to real assets such as gold or real estate, and another type are the ones tied to fiat currency held in reserves, in Szczepanik’s classification. The third and last category ...

he decided to see how practical it would be to mine Bitcoin with pencil and paper. It turns out that the SHA-256 algorithm used for mining is pretty simple and can in fact be done by hand. Not surprisingly, the process is extremely slow compared to hardware mining and is entirely impractical. But performing the algorithm manually is a good way to understand exactly how it works. The mining process Bitcoin mining is a key part of the security of the Bitcoin system. The idea is that Bitcoin miners group a bunch of Bitcoin transactions into a block, then repeatedly perform a cryptographic operation called hashing zillions of times until someone finds a special extremely rare hash value. At this point, the block has been mined and becomes part of the Bitcoin block chain. The hashing task itself doesn't accomplish anything useful in itself, but because finding a successful block is so difficult, it ensures that no individual has the resources to take over the Bitcoin system. For...

A stock exchange is a complex beast, but much of it can be reduced to a single data structure: the Order Book. A Bitcoin exchange uses the same data structure when trading currency pairs of USD, BTC, or ETH. This article will show you how to: Design an order book that can handle limit orders and market orders Install automated sanity checks that run on every write to the order book, preventing hacks and implementation bugs Build an HTTP API that people can use to interact with the order book We won’t work with actual bitcoins or wallets, since they add a lot of complexity and risk without making the article any more interesting. Instead, we’ll assume the “billing code” has already been written and focus only on the order book portion of the exchange. Types So what is an order book, really? First we’ll define our orders: import Data.Tagged import qualified Data.Map as M import qualified Data.Sequence as Q type UserId = Integer type Currency = Text ty...