Algorithms, step-by-step processes designed to tell a computer what to do and how to do it, are used to encipher data. Passwords and crypto keys are strings of characters needed to decrypt enciphered data. If these strings are not properly managed, you can lose the ability to decrypt this data forever. That is why proper key management is so important any time you are using cryptography on your systems. When using Blockchain, it can be especially important.
The most notable use of Blockchain to date is in Cryptocurrency. Last December, the 30-year-old founder of the Canadian cryptocurrency exchange QuadrigaCX reportedly died abroad. Unfortunately, he went to his reward without telling anyone the password for his storage wallet, causing the loss of up to 190 million dollars. What a mess! The exchange is now out of business and the court has appointed a monitor (Ernst & Young) and law firms to represent QuadrigaCX customers. An object lesson indeed for employing proper key management.