Check out the other chapters in the Communication Series: The Cryptography Handbook
In our day-to-day lives, the use of cryptography is everywhere. For example, we use it to securely send passwords over vast networks for online purchases. Bank servers and e-mail clients save your passwords using cryptography as well. Cryptography is used to secure all transmitted information in our IoT-connected world, to authenticate people and devices, and devices to other devices.
If all of the cryptographic engines/functions stopped working for a day, modern life as we know it would stop. Bank transactions wouldn’t go through, internet traffic would come to a halt, and cell phones would no longer function. At this point, all of our important information would be exposed, and it then could be exploited to do unimaginable harm to us all.