The private key can be printed as a series of letters and numbers, a seed phrase, or a 2D barcode. Usually, the public key or bitcoin address is also printed, so that a holder of a paper wallet can check or add funds without exposing the private key to a device. Several news outlets have asserted that the popularity of bitcoins hinges on the ability to use them to purchase illegal goods. Nobel-prize winning economist Joseph Stiglitz says that bitcoin’s anonymity encourages money laundering and other crimes. Read more about how do you mine litecoin here. According to, in 2017, there were 9,272 bitcoin wallets with more than $1 million