Patent ID: 8045714

Claim:
A processor-implemented method for managing multiple keys for file encryption and decryption, the method comprising: providing, via the processor, a key list for maintaining key history; storing in the key list, a first key useable for decrypting a first file; encrypting the key list with a second key useable for decrypting a second file that is different than the first file, the second key being different from the first key; executing a first re-keying operation comprising: decrypting the key list with the second key; retrieving the first key from the key list; decrypting the first file using the first key; and encrypting the first file using a third key, the third key being used as a current key for file encryption and being different from the first key and the second key; executing a second re-keying operation comprising: retrieving the second key; decrypting the second file using the second key; and encrypting the second file using the third key; storing the second key in the key list; and encrypting the key list with the third key, the third key useable thereafter for decrypting the first file, the second file, and the key list.