Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
194 words
A system for reproducing in a descrambler a subscriber key signal that is unique to the descrambler and was used in encrypting a key signal that must be decrypted for use in descrambling a signal received by the descrambler, wherein the scrambled signal is received by the descrambler together with the encrypted key signal, a key generation number and an address for accessing a predetermined area in a memory contained in the descrambler, the system comprising means for providing a subscriber key generation signal that is unique to the descrambler; a subscriber key generator for reproducing said unique subscriber key signal by processing the subscriber key generation signal in accordance with a predetermined encryption algorithm upon said algorithm being keyed by a prescribed subscriber key seed signal that is unique to the descrambler; a first memory storing the prescribed subscriber key seed signal, and for providing the prescribed seed signal to key the algorithm when the area of the memory containing the prescribed seed signal is accessed by the address received with the received key generation number; and means for accessing the first memory with the address received with the received key generation number.
Claim 2
Independent Claim
194 words
A system for reproducing in a descrambler a subscriber key signal that is unique to the descrambler and was used in encrypting a key signal that must be decrypted for use in descrambling a signal received by the descrambler, wherein the scrambled signal is received by the descrambler together with the encrypted key signal, a key generation number and an address for accessing a predetermined area in a memory contained in the descrambler, the system comprising means for providing a subscriber key generation signal that is unique to the descrambler; a subscriber key generator for reproducing said unique subscriber key signal by processing the subscriber key generation signal in accordance with a predetermined encryption algorithm upon said algorithm being keyed by a prescribed subscriber key seed signal that is unique to the descrambler; a first memory storing the prescribed subscriber key seed signal, and for providing the prescribed seed signal to key the algorithm when the area of the memory containing the prescribed seed signal is accessed by the address received with the received key generation number; and means for accessing the first memory with the address received with the received key generation number.
Claim 3
Dependent Claim
46 words
A system according to Claim 1, wherein the first memory stores a plurality of different subscriber key seed signals, _ with the prescribed one of said seed signals being provided to key the algorithm in accordance with the address received with the received key generation number.
Claim 4
Independent Claim
16 words
A system according to Claims 1 or 2, wherein the first memory is a secure memory.
Claim 5
Independent Claim
55 words
A system according to Claims 1,2 or 3, wherein the means for providing the subscriber key generation signal comprises a second memory storing a subscriber address signal that is unique to the descrambler; and means for combining the stored subscriber address signal and the received key generation number to provide the subscriber key generation signal.
Claim 6
Independent Claim
126 words
A system according to Claims 1, 2 or 3, wherein the means for providing the subscriber key generation signal comprises a second key generator for producing the subscriber key generation signal by processing a signal derived from a signal containing a subscriber address that is unique to the descrambler in accordance with a second predetermined encryption algorithm upon said second algorithm being keyed by a second prescribed key seed signal that is unique to the descrambler; and wherein the first memory also stores the second prescribed seed signal and provides the second prescribed seed signal to key the second algorithm when the area of the first memory containing the second prescribed seed signal also is accessed by the address received with the received key generation number.
Claim 7
Dependent Claim
54 words
A system according to Claim 5, wherein the means for providing the subscriber key generation signal further comprises a second memory storing a subscriber address signal that is unique to the descrambler; and means for combining the stored subscriber address signal and the received key generation number to provide said subscriber address containing signal.
Claim 8
Dependent Claim
117 words
A system according to Claim 6, wherein the means for providing the subscriber key generation signal further comprises a third key generator for producing said signal derived from said subscriber address containing signal by processing said subscriber address containing signal in accordance with a third predetermined encryption algorithm upon said third algorithm being keyed by a prescribed key seed signal that is stored in the first memory and is unique to the descrambler; and wherein the first memory provides the prescribed key seed signal for keying the third algorithm when the area of the first memory containing said seed signal for keying the third algorithm is accessed by the address received with the received key generation number.
Claim 9
Dependent Claim
26 words
A system according to Claim 7, wherein the same prescribed key seed signal is provided by the the first memory for keying two of the algorithms.