US Patent 8379850 Method and integrated circuit for secure encryption and decryption

In one embodiment, a cryptographic device is provided. The cryptographic device includes a persistent memory and a decryption control circuit coupled to the persistent memory. The decryption control circuit is configured to receive an encrypted data stream and decrypt a first portion of the encrypted data stream using a first cryptographic key stored in the persistent memory, the first portion including a second cryptographic key. The decryption circuit is configured to decrypt a second portion of the encrypted data stream using the second cryptographic key, the second portion of the encrypted data stream including payload data.