Data confidentiality is a requirement in the design of many embedded Linux devices. And encryption plays a significant role in developing products where confidentiality is a must. But there are different approaches, methods, and algorithms depending on the problem, which is not always clear to the developer. Should we use symmetric or asymmetric key encryption? What are the best algorithms for a specific situation? How to store the encryption key? In this talk, we will answer these and many other questions, covering the most common problems a developer could face to protect data-at-rest and data-in-transit when designing an embedded Linux device.