Patent ID: 7831051

Claim:
A method for secure communication between a secure hardware device connected to a computer and said computer, said method comprising the steps of: a) defining a group of secret sets including at least two secret sets, each of which includes a symmetric key and an assigned identifier, b) storing the group of secret sets in the secure hardware device in such a manner that the secure hardware device retrieves the symmetric key of any of said secret sets from the assigned identifier, c) selecting a first one of said secret sets and storing said selected first secret set in a first application, d) delivering the first application which includes the first secret set to a user who executes the first application on a computer being connected to the secure hardware device, e) wherein the first application defines a first session key and generates first session key indication data based on the first secret set, said first session key indication data including the identifier of the first secret set as the only element from the first secret set, and transmits said first session key indication data to the secure hardware device, which retrieves the symmetric key of the first secret set using the identifier included in said first session key indication data, and uses the retrieved symmetric key to set up the first session key, so that for secure communication the first session key is used as a symmetric key for encrypting and decrypting of data transmitted between the secure hardware device and the computer; f) selecting a second one of said secret sets and storing said selected second secret set in a second application, g) delivering said second application to said user executing the second application on a computer connected to the secure hardware device, h) wherein the second application defines a second session key and generates second session key indication data based on the second secret set, said second session key indication data including the identifier of the second secret set as the only element from the second secret set, and transmits said second session key indication data to the secure hardware device, which retrieves the symmetric key of the second secret set using the identifier included in the second session key indication data and uses the retrieved symmetric key of the second secret set to set up the second session key, so that for secure communication the second session key is used as a second symmetric key for encrypting and decrypting of data transmitted between the secure hardware device and the computer.