Method and system for secure key exchange using physically unclonable function (PUF)-based keys

1. A method, comprising:

retrieving a registered response obtained in a registration process, the registered response being a physically unclonable function (PUF)-based response associated with a device;

retrieving a registered helper data obtained in the registration process, the registered helper data corresponding to the registered response;

generating a cipher text by encrypting a message with the registered response;

sending to the device over a public channel the cipher text with the registered helper data;

receiving the cipher text with the registered helper data;

generating a noisy response;

reshaping the noisy response to obtain the registered response by using the registered helper data; and

decrypting the cipher text to obtain the message by using the registered response.

2. The method according to claim 1 , wherein the registration process comprises:

generating a pair of public key and secret key;

sending the public key to the device; and

receiving a cipher text from the device, the received cipher text generated at the device by using the public key to encrypt a response and a helper data corresponding to the response.

3. The method according to claim 2 further comprising:

decrypting the received cipher text by using the secret key to obtain a message in the received cipher text; and

storing the response and the helper data.

4. The method according to claim 2 further comprising:

sending a challenge together with the public key to the device.

5. The method according to claim 1 , wherein the registration process comprises:

receiving a public key sent from a server;

generating a response and a helper data in response to the public key;

generating a cipher text by using the public key to encrypt the response and the helper data; and

sending the generated cipher text to the server.

6. The method according to claim 5 further comprising:

concatenating the response and the helper data before encrypting the response and the helper data.

7. The method according to claim 1 , wherein the PUF-based response includes a built-in response in the device.

8. The method according to claim 1 , wherein the PUF-based response includes a response generated at the device in response to a challenge from a server.

9. A method, comprising:

generating a noisy response, the noisy response being a noise version of a registered response having been registered with a server in a registration process;

generating a helper data corresponding to the noisy response;

generating a cipher text by encrypting a message with the noisy response;

sending to the server over a public channel the cipher text with the helper data;

receiving the cipher text and the helper data;

deriving the noisy response from the registered response by using the helper data received; and

decrypting the cipher text to obtain the message by using the noisy response.

10. The method according to claim 9 further comprising:

receiving the cipher text and the helper data;

determining that the helper data received is identical with a registered helper data corresponding to the registered response; and

decrypting the cipher text to obtain the message by using the registered response.

11. The method according to claim 9 further comprising:

receiving a challenge together with a public key during the registration process.

12. The method according to claim 11 , wherein the registered response includes a response generated in response to the received challenge.

13. A system, comprising:

a physical server configured to:

retrieve a registered response obtained in a registration process, the registered response being a physically unclonable function (PUF)-based response associated with an integrated circuit (IC) device;

retrieve a registered helper data obtained in the registration process, the registered helper data corresponding to the registered response;

generate a cipher text by encrypting a message with the registered response; and

send to the IC device over a public channel the cipher text with the registered helper data,

wherein the IC device is configured to:

receive the cipher text with the registered helper data;

generate a noisy response;

reshape the noisy response to obtain the registered response by using the registered helper data; and

decrypt the cipher text to obtain the message by using the registered response.

14. The system according to claim 13 , wherein the physical server is further configured to, during the registration process:

generate a pair of public key and secret key;

send the public key to the IC device; and

receive a cipher text from the IC device, the received cipher text generated at the IC device by using the public key to encrypt a response and a helper data corresponding to the response.

15. The system according to claim 14 , wherein the physical server is further configured to, during the registration process:

decrypt the received cipher text by using the secret key to obtain a message in the received cipher text; and

store the response and the helper data.

16. The system according to claim 14 , wherein the physical server is further configured to, during the registration process:

send a challenge together with the public key to the IC device.

17. The system according to claim 13 , wherein the IC device is configured to, during the registration process:

receive a public key sent from the physical server;

generate a response and a helper data in response to the public key received;

generate a cipher text by using the public key to encrypt the response and the helper data; and

send the generated cipher text to the physical server.