Patent ID: 9154481
Filing Date: 2015-10-06
Classification: H04L

Abstract:
1. A method comprising: decrypting encoded information under a first cryptographic key from a collection of multiple cryptographic keys on a first cryptographic device to access a protected resource, wherein the first cryptographic device comprises one of a radio-frequency identification tag and a near-field communication tag, wherein each cryptographic key in the collection is associated with one or more sub-keys, and wherein the first cryptographic key is read from the first cryptographic device subsequent to authenticating to the first cryptographic device by (i) reading all of the one or more sub-keys associated with the first cryptographic key from the first cryptographic device and (ii) matching all of the one or more sub-keys associated with the first cryptographic key to one or more maintained sub-keys; rendering null all of the one or more sub-keys associated with the first cryptographic key; erasing the first cryptographic key; transmitting, to the first cryptographic device, a command to modify each of the one or more sub-keys associated with each remaining cryptographic key in the collection of cryptographic keys; selecting a second cryptographic key from the collection of multiple cryptographic keys on the first cryptographic device; and encrypting the protected resource under the second cryptographic key, wherein the second cryptographic key is read from the first cryptographic device subsequent to authenticating to the first cryptographic device by (i) reading all of the one or more modified sub-keys associated with the second cryptographic key from the first cryptographic device and (ii) matching all of the one or more sub-keys associated with the second cryptographic key to one or more maintained sub-keys.