Can the PUF digital fingerprint of LPC55S69 be used to generate public-private key pairs

[Moyu]

Hi,

I have studied the part of PUF in SDK of LPC55S69,found that only the PUF response can generate a single key, and then send it to the AES engine through the hardware bus for use.

I want to ask if there is a tool library that uses the PUF response to generate a pair of public-private key pairs. I want to use it for asymmetric encryption.

If there is no corresponding library, I hope that experts can provide some ideas for generating public-private key pairs.

Thanks,

Moyu

[Pavel_Hernandez]

Hello, my name is Pavel, and I will be supporting your case, I review your information and I found this app note [AN12324] if you are not familiar with the PUF I recommend reviewing all information if yes, review chapter 3.4 has an option with a GUI tool or if you are familiar with the command, I recommend us the SPSDK it has more intuitive options.

Best regards,
Pavel

[Moyu]

Hi Pavel，

I did check the manual of AN12324 before, but the GUI tools in the manual you mentioned do not seem to be very helpful to my questions, because there is no option to generate asymmetric encryption keys in the tool settings.

I discussed with others in other hardware forums and got the information that using the puf_GETKEY function in the puf_demo in the official SDK of LPC55S69 seems to get all the keys except  the key which index is keyIndex_00, is this correct？

Thanks，

Moyu

[Pavel_Hernandez]

Hello, sorry I think I do not explain, about your question, yes, as you can see in the app note the index 0 is a special case because the command is sent to this periphery through a secure bus. I do not if you review the SW test, to review the examples.

A special case is using a key index of 0 to instruct the GetKey command to send the decrypted key into one of the peripheries (AES or PRINCEx) through the internal secure bus or to the AHB

Best regards,
Pavel

[zhliao]

Hi Moyu,

I am trying to read out the PUF fingerprint and found this thread. Thank you very much for your comments. May I ask which forum you got this feedback from? Besides, I wanted to find a comprehensive SDK document for the LPC55S69 board but did not make progress. Do you have any suggestions?

Thanks,

Zhonghao

[Moyu]

Hi Zhonghao,

I have discussed this issue with NXP development engineers and have come to the conclusion that the PUF function of this development board is not a traditional PUF function, so it is meaningless to attempt to extract PUF fingerprints. If you are a Chinese, you can visit the NXP China Forum, where many enthusiastic engineers can help you. Regarding development documentation, currently only AN12224SW is available, but it can not solve your problem.

I am also interested in extracting PUF fingerprints. If you have a breakthrough, we can discuss it.

Thanks，

Moyu

[zhliao]

Hi Moyu,

Thank you for your response. I checked NXP China Forum and found a similar question published on March 1st. Not sure if it was you who asked the question, but that question was very similar to ours. I will keep an eye on this topic and let you know if I make any progress.

Thanks,

Zhonghao