On June 19, cryptocurrency exchange website Bithumb posted a series of tweets declaring that it was disabling its deposit and withdrawal services due to safety issues and asked its users to avoid depositing funds in their wallets until further notice. It later became evident that hackers had breached the South Korea–based exchange and had stolen $30 million worth of cryptocurrency from users’ wallets.
Bithumb can consider itself lucky. In eight years since the founding of the first online bitcoin exchange, there have been many similar hacks, some of them worth several hundred million dollars.
Most users store their bitcoins and digital currencies in online exchanges such as Coinbase, Bitfinex and Kraken. Online exchanges assume responsibility for storing and securing the funds of their users. This provides a convenient experience to the users of those exchanges, many of whom have minimal or no knowledge of cryptography, but it also makes them a very attractive target to cybercriminals seeking to lay their hands on a large amount of hard-to-trace money.
That’s why users who want to take the security of their bitcoins into their own hands use "cold storages," offline stores that aren’t accessible to hackers. One of the more popular types of cold storage is “paper wallets,” which, as the name suggests, are bitcoin wallets made of paper (although they can be made of plastic or metal or any other suitable material). Paper wallets are impervious to online hacks and cyber-attacks, but they come with their own caveats.
What is a paper wallet?
Read more here: https://amity.io/blog/how-to-make-a-paper-wallet/