Anti-splitter violation conditional key change

摘要

Systems and methods are disclosed for performing anti-piracy countermeasures in order to prevent unauthorized access of protected content. A conditional access system may be modified to include a counter. The counter is incremented every time the conditional access system receives a request that is a potential indication of pirate activity. The counter may also be decremented every time the conditional access system receives a request indicative of legitimate activity. If the conditional access system receives a management message containing a key required to access content keys, the conditional access system cheeks the counter. If the counter is below a threshold value, the conditional access system obtains the key. However, if the counter is above the threshold value, the conditional access system disregards the key contained in the management message, thereby losing access to protected content.

主权项

1. A computer-implemented method for performing a control word sharing countermeasure, the method comprising:
establishing a counter; receiving a first encrypted control message, wherein the first encrypted control message corresponds to a first channel; receiving a second encrypted control message; determining whether the second encrypted control message corresponds to the first channel; when the second message does not correspond to the first channel, incrementing the counter by a first value; when the second control message corresponds to the first channel, decrementing the counter by a second value, wherein the second value is different from the first value; receiving an encrypted management message, wherein the encrypted management message contains a key for decrypting one or more encrypted control messages; determining whether a value of the counter is below a threshold value; and when the value of the counter is below the threshold value:
decrypting the encrypted management message to retrieve the key; anddecrypting at least a third encrypted message using the key.