System and method for licensing and for measuring use of an IP block

1. An integrated circuit comprising:

one or more protected circuits;

a license control circuit configured to request, from a license issuer, a license for activating the one or more protected circuits, the license request comprising a first seed value;

a seed memory configured to store the first seed value;

and

a cryptographic circuit configured to verify the authenticity of a license received from the license issuer based on the first seed value, wherein the license control circuit is configured:

to receive the license;

to impose a validity limit on the received license, and to request a new license from the license issuer before the validity limit of the received license, the new license request comprising a new seed value;

to store the new seed value to the seed memory; and

to delete from the seed memory the first seed value after the validity limit of the received license.

2. The integrated circuit of claim 1 , wherein the received license comprises a message authentication code and wherein the cryptographic circuit is configured to verify the authenticity of the license by verifying the message authentication code using the first seed value stored in the seed memory.

3. The integrated circuit of claim 1 , further comprising a random value generator adapted to generate a random or pseudo-random value, wherein the license control circuit is configured to generate the first seed value based on the random or pseudo-random value.

4. The integrated circuit of claim 1 , wherein the first seed value comprises a device identifier identifying the integrated circuit.

5. The integrated circuit of claim 1 , wherein the license comprises a verification code, the integrated circuit further comprising a circuit activation module adapted to activate a first of the one or more protected circuits by loading an activation code into an activation register associated with the first protected circuit based on a verification of the verification code.

6. The integrated circuit of claim 5 , wherein the cryptographic circuit is further adapted to:

derive a device key from the first seed value; and

decrypt the received license using the device key in order to extract the verification code.

7. The integrated circuit of claim 1 , further comprising a metering data generator configured to receive one or more count values relating to the activity of the one or more protected circuits, and to generate metering data based on said one or more count values.

8. The integrated circuit of claim 7 , wherein the license control circuit is further configured to:

include the metering data in the request for a new license from the license issuer; and/or

determine the validity limit of a received license based on the metering data.

9. A method of applying a license to one or more protected circuits of an integrated circuit, the method comprising:

requesting, by a license control circuit of the integrated circuit from a license issuer, a license for activating the one or more protected circuits, the license request comprising a first seed value;

storing the first seed value in a seed memory;

receiving, by the license control circuit, the license;

verifying the authenticity of a license received from the license issuer based on the first seed value;

imposing a validity limit on the received license and requesting a new license from the license issuer before the validity limit of the received license, the new license request comprising a new seed value; and

deleting from the seed memory the first seed value after the validity limit of the received license.