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US 4,670,857 AGranted
Cartridge-controlled system whose use is limited to authorized cartridges
OwnerMichael I. Rackmaninventor
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OwnerMichael I. Rackmaninventor
Estimating the term…
A cartridge-controlled system whose use is limited to authorized cartridges. Blocks of instructions of a program designed to run on the machine are encrypted by the machine manufacturer using the private key of a public-key cryptosystem pair. The machine, during an initialization step following the insertion of a new cartridge, decrypts information strings stored in the cartridge through use of the associated public key, and stores the resulting decrypted instructions in random access memory. The machine microprocessor then accesses the instructions in the random access memory. Although the public key may be widely known, as long as the private key is kept secret, there is no way for an unauthorized software/cartridge supplier to encrypt a program such that following decryption in the machine there will result an intelligible sequence of instructions.
A plurality of mass-produced identical systems each comprising data processing means for generating memory-accessing address signals and for executing memory-furnished instructions;
A method for allowing the manufacturer of a plurality of mass-produced identical ROM-cartridge controlled machines to prevent unauthorized persons from manufacturing original ROM cartridges capable of controlling machine operations, each machine including a read-write memory for storing the instructions which control the machine operation, comprising the steps of (1) controlling each machine (a) to read from a ROM cartriage blocks of encrypted instructions, to decrypt the blocks of instructions thus read, and to store the decrypted blocks of instructions in the read-write memory, and (b) thereafter to execute instructions accessed from the read-write memory, and (2) encrypting blocks of the actual instructions to be executed by any machine and storing the encrypted blocks of instructions in a ROM cartridge to be used to control any machine operation, the encryption and decryption steps being carried out respectively in accordance with the private and public keys of a public-key cryptosystem pair;
A plurality of mass-produced identical systems each comprising data processing means for generating memory-accessing address signals and for executing memory-furnished instructions;
A method for allowing the manufacturer of a plurality of mass-produced identical machines controlled by instructions contained in an insertable storage medium to prevent unauthorized persons from manufacturing original storage media capable of controlling machine operations, each machine including a read-write memory for storing instructions which control the machine operation, comprising the steps of (1) controlling each machine (a) to read from an inserted storage medium blocks of encrypted instructions, to decrypt the blocks of instructions thus read, and to store the decrypted blocks of instructions in the read-write memory, and (b) thereafter to execute instructions accessed from the read-write memory, and (2) encrypting blocks of the actual instructions to be executed by any machine and storing the encrypted blocks of instructions in a storage medium to be used to control any machine operation, the encryption and decryption steps being carried out respectively in accordance with the private and public keys of a public-key cryptosystem pair;
Dependencies are inferred from the claim text.