Patent ID: 7657033

Claim:
A machine-implemented method implemented on a sender machine having a processor and a memory, the method comprising: the processor encrypting a first segment of a message, therein forming an encrypted first message segment, wherein the sender machine, which is at a first location, has possession of a first group of keys, the first group of keys includes a first set of keys that were not previously used for encryption in a transmission of the message to a receiver machine, and at least one more key that was previously used for encryption in a prior transmission as part of sending the message to the receiver machine, the sender machine, at the first location, has possession of a second set of keys that have been previously transmitted to the receiver machine as part of sending the message to the receiver machine, the encrypted message segment is encrypted with at least one key from the first group of keys, the first set of keys includes at least one key, and the second set of keys includes at least one key; the processor encrypting the second set of keys with the first group of keys, therein forming an encrypted second set of keys, each key of the first group of keys being used in the encrypting of the first message segment or the encrypting of the second set of keys; the processor encrypting a second message segment with at least one key from a second group of keys, therein forming a second encrypted message segment, wherein the second group of keys includes the second set of keys and at least one other key; and the processor encrypting a third set of keys with the second set of keys, therein forming an encrypted third set of keys.