Patent ID: 9705854
Date: 2017-07-11
CPC Classifications: G06F,H04L

Claim:
1. A method for operating a secure integrated circuit having a plurality of mutually exclusive circuit zones, each circuit zone being associated with a region of circuitry on the integrated circuit where the regions of circuitry of the plurality of circuit zones are mutually exclusive, the integrated circuit including a first circuit zone having a first level of security and a second circuit zone having a second level of security less than the first level of security, the method comprising unpacking a key exchange package, the unpacking including: receiving a key exchange package in the second circuit zone, the key exchange package including encrypted key data, and encrypted key associated data; processing the encrypted key data using a content key in the first circuit zone to generate decrypted key data and storing the decrypted key data in the first circuit zone without disclosing the decrypted key data into the second circuit zone; processing a data item in the first circuit zone with a non-invertible function to generate a modified data item and storing the modified data item in the second circuit zone, and processing the encrypted key associated data using the modified data item to generate decrypted key associated data and storing the decrypted key associated data in the second circuit zone; wherein the secure integrated circuit includes a plurality of gate circuits providing circuit level enforcement of a limited transfer of data between the circuit zones, the gate circuits providing the only data paths between the first circuit zone and the second circuit zone and preventing unmodified transfer of data from the first circuit zone to the second circuit zone and processing the encrypted key data using the content key to generate the decrypted key data includes using a decryption gate circuit to decrypt the encrypted key data using the content key.