Authenticating a message in a wireless communication system

1. A method for authenticating a message received by a recipient radio node in a wireless communication system, the method comprising an authentication node:

determining a radio resource that carries the message received by the recipient radio node;

performing authentication of the message by checking whether the message is bound to the determined radio resource; and

receiving binding information associated with the message,

wherein the binding information indicates a radio resource on which the message is restricted to being carried, and

wherein the checking comprises checking whether the determined radio resource matches the radio resource indicated by the binding information.

2. The method of claim 1 , wherein the checking comprises checking whether the message is cryptographically bound to the determined radio resource.

3. The method of claim 1 , wherein the checking comprises:

computing an expected authentication or integrity code based on information identifying the determined radio resource; and

checking whether the expected authentication or integrity code matches an authentication or integrity code associated with the message.

4. The method of claim 1 , wherein the checking comprises checking whether a radio resource on which the message was sent to the recipient radio node, or a radio resource on which the message was expected to be received by the recipient radio node, corresponds to a radio resource on which the message was received by the recipient radio node.

5. The method of claim 1 :

further comprising receiving binding information indicating a radio resource on which a sender radio node transmitted the message to the recipient radio node,

wherein the determining comprises determining the radio resource that carries the message as being a radio resource on which the recipient radio node received the message from the sender radio node; and

wherein the checking comprises checking whether the radio resource on which the recipient radio node received the message corresponds to the radio resource on which the sender radio node transmitted the message, as indicated by the binding information.

6. The method of claim 1 , wherein the determining comprises determining the radio resource that carries the message as being a radio resource on which the message is received by the recipient radio node.

7. The method of claim 1 , wherein the determining comprises determining the radio resource that carries the message as being a radio resource on which the message was expected to have been transmitted to the recipient radio node.

8. The method of claim 7 , further comprising determining the radio resource on which the message was expected to have been transmitted to the recipient radio node, by:

determining a radio resource on which the message is received by the recipient radio node;

determining the radio resource on which the message was expected to have been transmitted to the recipient radio node, as being a radio resource which is offset by a determined amount from the radio resource on which the message is received by the recipient radio node.

9. The method of claim 1 , further comprises transmitting, to the recipient radio node, information that indicates a result of the authentication or information whose transmission is conditioned upon the message being authenticated.

10. The method of claim 1 :

wherein the authentication node is the recipient radio node;

wherein the method further comprises receiving the message and processing the message responsive to authenticating the message.

11. A method for securing transmission of a message from a sender radio node to a recipient radio node in a wireless communication system, the method comprising the sender radio node:

determining a radio resource that carries the message to the recipient radio node;

binding the message to the determined radio resource for authenticity, wherein the binding comprises generating binding information that indicates that the message is restricted to being carried on the determined radio resource;

transmitting the binding information to an authentication node configured to authenticate the message using the binding information; and

transmitting the bound message to the recipient radio node on the determined radio resource.

12. An authentication node for authenticating a message received by a recipient radio node in a wireless communication system, the authentication node comprising:

processing circuitry;

memory containing instructions executable by the processing circuitry whereby the authentication node is operative to:

determine a radio resource that carries the message received by the recipient radio node;

perform authentication of the message by checking whether the message is bound to the determined radio resource; and

receive binding information associated with the message,

wherein the binding information indicates a radio resource on which the message is restricted to being carried, and

wherein the checking comprises checking whether the determined radio resource matches the radio resource indicated by the binding information.

13. A sender radio node for securing transmission of a message from the sender radio node to a recipient radio node in a wireless communication system, the sender radio node comprising:

processing circuitry;

memory containing instructions executable by the processing circuitry whereby the sender radio node is operative to:

determine a radio resource that carries the message to the recipient radio node;

bind the message to the determined radio resource, wherein the binding comprises generating binding information that indicates that the message is restricted to being carried on the determined radio resource

transmit the binding information to an authentication node configured to authenticate the message using the binding information; and

transmit the cryptographically bound message to the recipient radio node on the determined radio resource.

14. A non-transitory computer readable recording medium storing a computer program product for controlling an authentication node for authenticating a message received by a recipient radio node in a wireless communication system, the computer program product comprising software instructions which, when run on processing circuitry of the authentication node, causes the authentication node to:

determine a radio resource that carries the message received by the recipient radio node;

perform authentication of the message by checking whether the message is bound to the determined radio resource; and

receive binding information associated with the message,

wherein the binding information indicates a radio resource on which the message is restricted to being carried, and

wherein the checking comprises checking whether the determined radio resource matches the radio resource indicated by the binding information.