A trove of documents handed over to an investigative news agency by whistleblower Edward Snowden has revealed that keeping track of bitcoin transactions and users was “#1 priority” for the US National Security Agency (NSA). The documents are of the same bunch which Snowden exposed long back that led Edward Snowden to attain worldwide popularity. As per the, heavily redacted documents published by The Intercept, the NSA used a special software to target bitcoin users. A per a memo, in order to track bitcoin users the NSA not just followed the public ledger (called blockchain) which stores all the information about the transaction except the real identities, it also collected some bitcoin users’ password information, internet activity, and a type of unique device identification number known as a MAC address. The documents talk about a data source which provides the agency with ‘MAC addresses, password hash history, provider users and user sessions’. The agency sought more information and user validation from its source.
— source moneycontrol.com