Method of validating consumable authentication chip
First Claim
1. A method of validating a consumable authentication integrated circuit, the method comprising the steps of:
- calling, in a trusted authentication integrated circuit, a test function multiple times with a known incorrect value, the test function either generating an expected invalid response or not generating an expected invalid response and invalidating the consumable integrated circuit;
if the invalid response is generated, in the trusted integrated circuit, generating a secret random number and calculating its signature using a signature function;
encrypting, in the trusted integrated circuit, the random number and its signature using a symmetric encryption function with a first secret key;
calling, in the consumable integrated circuit, a read function with the encrypted random number and signature from the trusted integrated circuit, the read function;
decrypting the encrypted random number and signature using a symmetric decryption function with the first secret key;
calculating a signature for the decrypted random number using the signature function;
comparing the calculated and decrypted signatures; and
if the signatures match, encrypting the decrypted random number and a data message read from the consumable integrated circuit using the symmetric encryption function with a second secret key;
calling, in the trusted integrated circuit, the test function with the data message and the encrypted random number and data message from the consumable integrated circuit, the test function;
encrypting the random number and the data message using the symmetric encryption function with the second secret key;
comparing the encrypted random numbers and data messages;
if they match, validating the consumable integrated circuit; and
if they do not match, invalidating the consumable integrated circuit.
3 Assignments
0 Petitions
Accused Products
Abstract
A method of validating a consumable authentication chip is provided having the steps of: numerously calling a trusted chip'"'"'s test function with an incorrect value to generate an invalid response or not generate the response thereby invalidating the consumable chip; if generated, in the trusted chip, generating a secret random number, calculating its signature and symmetrically encrypting the number/signature using a first secret key; calling the consumable chip'"'"'s read function with the encrypted number/signature to symmetrically decrypt the encrypted number/signature using the first key, calculate the decrypted number'"'"'s signature, compare the signatures, and if they match, symmetrically encrypt the decrypted random number and a data message using a second secret key; calling the trusted chip'"'"'s test function with the message and the encrypted number/message to symmetrically encrypt the number and message using the second key, compare the encrypted numbers/messages, validate the consumable chip if they match, and invalidate otherwise.
22 Citations
13 Claims
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1. A method of validating a consumable authentication integrated circuit, the method comprising the steps of:
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calling, in a trusted authentication integrated circuit, a test function multiple times with a known incorrect value, the test function either generating an expected invalid response or not generating an expected invalid response and invalidating the consumable integrated circuit; if the invalid response is generated, in the trusted integrated circuit, generating a secret random number and calculating its signature using a signature function; encrypting, in the trusted integrated circuit, the random number and its signature using a symmetric encryption function with a first secret key; calling, in the consumable integrated circuit, a read function with the encrypted random number and signature from the trusted integrated circuit, the read function; decrypting the encrypted random number and signature using a symmetric decryption function with the first secret key; calculating a signature for the decrypted random number using the signature function; comparing the calculated and decrypted signatures; and if the signatures match, encrypting the decrypted random number and a data message read from the consumable integrated circuit using the symmetric encryption function with a second secret key; calling, in the trusted integrated circuit, the test function with the data message and the encrypted random number and data message from the consumable integrated circuit, the test function; encrypting the random number and the data message using the symmetric encryption function with the second secret key; comparing the encrypted random numbers and data messages; if they match, validating the consumable integrated circuit; and if they do not match, invalidating the consumable integrated circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification