Method and apparatus for storing and distributing encryption keys
A first infrastructure system device other than a mobile station generates an encryption key and encrypts the encryption key with a first intrakey associated with a first zone that includes a second infrastructure system device other than a mobile station, yielding a first encrypted encryption key. The first intrakey is used only by infrastructure system devices other than a mobile station for encrypting at least the encryption key prior to transport within the first zone. The first infrastructure system device forwards the first encrypted encryption key to the second infrastructure system device.
1. A method comprising the steps of:
generating an encryption key at a first infrastructure system device other than a mobile station;
encrypting the encryption key with a first intrakey associated with a first zone that includes a second infrastructure system device other than a mobile station, yielding a first encrypted encryption key, wherein the first intrakey is used only by infrastructure system devices other than a mobile station for encrypting at least the encryption key prior to transport within the first zone; and
forwarding the first encrypted encryption key to the second infrastructure system device, wherein the step of forwarding comprises forwarding the first encrypted encryption key transparently through at least a third infrastructure system device other than a mobile station prior to the second infrastructure system device and storing the first encrypted encryption key at the third infrastructure system device.
2. The method of claim 1 , further comprising the steps of:
encrypting the encryption key with a second intrakey associated with a second zone that includes a fourth infrastructure system device other than a mobile station, yielding a second encrypted encryption key, wherein the second intrakey is used only by infrastructure system devices other than a mobile station for encrypting at least the encryption key prior to transport within the second zone; and
forwarding the second encrypted encryption key to the fourth infrastructure system device.
3. The method of claim 1 , wherein the third infrastructure system device is a zone manager.
4. The method of claim 1 , wherein the encryption key is a static cipher key that is used when at least one of dynamic air interface encryption and authentication is inoperable.
5. The method of claim 1 , wherein the first infrastructure system device is a key management facility.
6. The method of claim 1 , further comprising the step of forwarding an acknowledgment of receipt of the encryption key to the first infrastructure system device via at least a fifth infrastructure system device other than a mobile station.
7. The method of claim 6 , wherein the fifth infrastructure system device is an air traffic router.