Deriving a Symmetric Key from an Asymmetric Key for File Encryption or Decryption

摘要

One aspect relates to a process and associated device that provides a private key of an asymmetric key pair in a key device. A symmetric master key is derived from the private key of the asymmetric key pair. The symmetric master key is stored in a computer memory location. The symmetric master key is used to encrypt or decrypt a file encryption key. The file encryption key can encrypt or decrypt files. In another aspect, the user can still access the files even if a user deactivates the key device by encrypting or decrypting the file encryption key directly from the symmetric master key.