1. A user device, comprising: a processing core having at least one processor configured to, before a system reboot: decrypt a credential-protected key based on a user credential to generate a data protection key, wherein the user credential is received via an input device during an initial logon for a user to access a user resource; create a random token generated to last for a limited period of time to act as an ephemeral entropy; and encrypt the data protection key with the ephemeral entropy to produce an entropy-protected key; and a non-volatile data storage device to store the entropy-protected key prior to the system reboot, wherein the at least one processor is further configured to, based on the system reboot and after the system reboot, decrypt the entropy-protected key, stored in the non-volatile data storage, by using the ephemeral entropy to produce the data protection key, and access the user resource with the data protection key decrypted from the entropy-protected key after the system reboot without using a separate user credential from the data protection key decrypted using the ephemeral entropy.