Patent ID: 7904709

Claim:
A method of controlling data communications between a server and a client device, wherein the server is adapted to encrypt data using a first key and transmit encrypted data to the client device for decryption using a second key initially stored on the client device, the method comprising: receiving, at the client device, encrypted data from the server; attempting, at the client device, to decrypt encrypted data received at the client device using the second key; determining that the encrypted data was not decrypted using the second key; and in response to determining that the encrypted data was not decrypted using the second key, transmitting stop data stored on the client device from the client device to the server to indicate to the server that the encrypted data received by the client device from the server was not decrypted using the second key, wherein the stop data represents a command to the server to cease transmitting data encrypted with the first key to the client device; wherein the stop data is pre-encoded using a cryptographic operation, and stored on the client device prior to the receiving the encrypted data and prior to the determining that the encrypted data was not decrypted using the second key.