Encryption keys are responsible for encrypting and decrypting data, validating identities by authenticating users and devices, and securing transactions with digital signatures and certificates. As computing has become more powerful and sophisticated, new hardware attack vectors like Meltdown and Spectre have been discovered that exploit microprocessor vulnerabilities to access data. The concept of a single, well-defined security perimeter has been virtually obliterated by the trend towards cloud computing. When your resources are everywhere, your Root of Trust needs to be accessible from everywhere too.
Source: https://www.helpnetsecurity.com/2021/06/17/cryptographic-keys-safe/