# US 10,321,201 B2 · Methods and systems for re-securing a compromised channel in a satellite signal distribution environment

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- Number: US 10,321,201 B2
- Document ID: US10321201B2
- Status: Granted
- Kind: B2
- Application number: 15/496,470
- Filed: 2017-04-25
- Published: 2017-08-10
- Granted: 2019-06-11
- Earliest claimed: 2009-12-21
- Assignees: Bce Inc.
- Applicants: Bce Inc.
- Inventors: Ovidiu Octavian Popa; Alexander Ishankov; Alan Dagenais; Louie Andriano; Bratislav Becic; Tim Dinesen
- Web page: https://patentgrep.com/patent/US10321201B2

## CPC

- H04N 21/64715: {Protecting content from unauthorized alteration within the network (verifying the information received for network security in communication control or processing H04L63/12; integrity in wireless network security H04W12/10)}
- H04L 9/0861: {Generation of secret information including derivation or calculation of cryptographic keys or passwords}
- H04L 9/0891: {Revocation or update of secret information, e.g. encryption key update or rekeying}
- H04L 9/14: using a plurality of keys or algorithms
- H04L 9/30: Public key, i.e. encryption algorithm being computationally infeasible to invert or user's encryption keys not requiring secrecy
- H04L 9/3247: {involving digital signatures}
- H04L 63/0428: {wherein the data content is protected, e.g. by encrypting or encapsulating the payload}
- H04L 63/1408: {by monitoring network traffic (monitoring network traffic per se H04L43/00)}
- H04N 21/26606: {for generating or managing entitlement messages, e.g. Entitlement Control Message [ECM] or Entitlement Management Message [EMM] (arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14)}
- H04N 21/26613: {for generating or managing keys in general (key distribution for secret or secure communication involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP] H04L9/083; network support of key management H04L63/06; key management for network security in communication control or processing H04W12/04)}
- H04N 21/6143: {involving transmission via a satellite}
- H04N 21/6193: {involving transmission via a satellite (arrangements for data linking, networking or transporting, or for controlling an end to end session in a satellite broadcast system H04B7/18526)}
- H04N 21/64723: {Monitoring of network processes or resources, e.g. monitoring of network load (traffic related reporting in data switching networks H04L43/062)}
- H04L 2209/60: Digital content management, e.g. content distribution
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A method implemented by a set top box that encrypts communications for a channel stacking switch (CS) using a public key of the CSS, the method comprising: obtaining a message from a head end; extracting electronic counter measure (ECM) data from the message; sending the ECM data to the CSS; receiving, in response to the sending, a new public key of the CSS; encrypting communications for the CSS using the new public key of the CSS. Also, a method for implementation by a CSS, comprising: maintaining a private key and a public key; obtaining ECM data sent by a set top box in communication with the CSS; obtaining an identifier of the CSS; formulating a new public key based on the private key, the identifier and the ECM; rendering the new public key available to the set top box.

## Claims

### Claim 1

A set top box comprising:
a communications interface configured to communicate with a channel stacking switch over a communication channel, the channel stacking switch distributing satellite signals to a plurality of receivers; and
a processing entity configured to encrypt data destined for the channel stacking switch using a public key of the channel stacking switch, obtain a message from a head end via the communications interface, extract electronic counter measure (ECM) data from the message, send the ECM data to the channel stacking switch via the communication interface, receive a new public key of the channel stacking switch via the communications interface and begin encrypting subsequent data destined for the channel stacking switch using the new public key of the channel stacking switch.

### Claim 2 (depends on 1)

The set top box defined in claim 1, wherein the message is obtained from the head end via the channel stacking switch.

### Claim 3 (depends on 1)

The set top box defined in claim 1, wherein the ECM data is a 32 bit integer.

### Claim 4 (depends on 1)

The set top box defined in claim 1, wherein the message is obtained from the head end in response to an identified or suspected security breach.

### Claim 5 (depends on 1)

The set top box defined in claim 1, wherein the channel stacking switch is connected to a satellite signal receiver of a satellite signal distribution network.

### Claim 6

A non-transitory computer-readable storage medium storing instructions for execution by a computing entity of a set top box (STB) capable of encrypting communications for a channel stacking switch using a public key of the channel stacking switch, wherein execution of the instructions by the computing entity causes the STB to:
obtain a message from a head end;
extract electronic counter measure (ECM) data from the message;
send the ECM data to the channel stacking switch, the channel stacking switch distributing satellite signals to a plurality of receivers;
receive, in response to sending the ECM data to the channel stacking switch, a new public key of the channel stacking switch; and
encrypt communications destined for the channel stacking switch using the new public key of the channel stacking switch.

### Claim 7 (depends on 6)

The non-transitory computer-readable storage medium defined in claim 6, wherein the message is obtained from the head end via the channel stacking switch.

### Claim 8 (depends on 6)

The non-transitory computer-readable storage medium defined in claim 6, wherein the ECM data is a 32 bit integer.

### Claim 9 (depends on 6)

The non-transitory computer-readable storage medium defined in claim 6, wherein the message is obtained from the head end in response to an identified or suspected security breach.

### Claim 10 (depends on 6)

The non-transitory computer-readable storage medium defined in claim 6, wherein the channel stacking switch is connected to a satellite signal receiver of a satellite signal distribution network.

### Claim 11

A non-transitory computer-readable storage medium storing instructions for execution by a computing entity of a channel stacking switch (CSS) distributing satellite signals to a plurality of receivers, wherein execution of the instructions by the computing entity causes the CSS to:
maintain a private key and a public key;
obtain electronic counter measure (ECM) data sent by a set top box in communication with the channel stacking switch;
obtain an identifier of the channel stacking switch;
formulate a new public key based on the private key, the identifier and the ECM; and
render the new public key available to the set top box.

### Claim 12 (depends on 11)

The non-transitory computer-readable storage medium defined in claim 11, wherein execution of the instructions by the computing entity further causes the CSS to manage a memory in which the private key, the public key and the new public key are stored.

### Claim 13 (depends on 12)

The non-transitory computer-readable storage medium defined in claim 12, wherein execution of the instructions by the computing entity for managing the memory causes the CSS to replace the public key with the new public key in the memory.

### Claim 14 (depends on 11)

The non-transitory computer-readable storage medium defined in claim 11, wherein execution of the instructions by the computing entity further causes the CSS to carry out a pseudonymous signature scheme to formulate the new public key.

### Claim 15 (depends on 11)

The non-transitory computer-readable storage medium defined in claim 11, wherein execution of the instructions by the computing entity further causes the CSS to, prior to obtaining the ECM data, receive a message from a head end and forward the message to the set top box, the message comprising the ECM data.

### Claim 16 (depends on 11)

The non-transitory computer-readable storage medium defined in claim 11, wherein the identifier of the channel stacking switch comprises a hardware identifier.

### Claim 17 (depends on 11)

The non-transitory computer-readable storage medium defined in claim 11, wherein execution of the instructions by the computing entity further causes the CSS to decrypt data received from the set top box using the private key.

### Claim 18 (depends on 17)

The non-transitory computer-readable storage medium defined in claim 17, wherein prior to obtaining the ECM data, at least some of the data received from the set top box is encrypted using the public key and after rendering the new public key available to the set top box, at least some of the data received from the set top box is encrypted using the new public key.