Bitcoin is built on a distributed digital record called a blockchain. As the name implies, blockchain is a linked body of data, made up of units called blocks that contain information about each and every transaction, including date and time, total value, buyer and seller, and a unique identifying code for each exchange. Entries are strung together in chronological order, creating a digital chain of blocks. βOnce a block is added to the blockchain, it becomes accessible to anyone who wishes to view it, acting as a public ledger of cryptocurrency transactions,β says Stacey Harris, consultant for Pelicoin, a network of cryptocurrency ATMs. Blockchain is decentralized, which means itβs not controlled by any one organization. βItβs like a Google Doc that anyone can work on,β says Buchi Okoro, CEO and co-founder of African cryptocurrency exchange Quidax. βNobody owns it, but anyone who has a link can contribute to it. And as different people update it, your copy also gets updated.β
Mr. Durov launched Telegram in late 2013 with his brother, Nikolai, just months before he was pushed out of VK, the Russian social-media platform he founded. Mr. Durov pitched his new appβfunded with the proceeds from the VK saleβless as a business than as a way for people to send messages while avoiding government surveillance and censorship.
