topic Re: LPC55xx certificate：why so many RoT keys? in LPC Microcontrollers

LPC55xx certificate：why so many RoT keys?

wilsonyan2019 — Thu, 30 May 2019 15:30:02 GMT

Hi sir,

I am reading the AN12283 on LPC55xx certificate verification.

I want to know if the RoT keyx in the picture means the public key in the root CA certificate?

If so, why so many key slots? Isn't it only one root certificate and only one root key?

Thanks for help!

Wenchuan

Re: LPC55xx certificate：why so many RoT keys?

ZhangJennie — Mon, 03 Jun 2019 09:03:03 GMT

Wenchuan Yan,

>>I want to know if the RoT keyx in the picture means the public key in the root CA certificate?

Yes, RoT keyx is public key.

>>If so, why so many key slots? Isn't it only one root certificate and only one root key?

in case the Key0 private key is leaked, key0 public is no longer usable. in this case, we can use other keys.

It's true one key0 can work for this function. if you don't need other keys, just set them as 0.

BTW, what application do you work with LPC55sxx?

Have a great day,
Jun Zhang

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Re: LPC55xx certificate：why so many RoT keys?

wilsonyan2019 — Wed, 05 Jun 2019 08:36:12 GMT

Hi Jun,

Thanks for your reply.

And one more thing to ask. In lpc55xx certificate chain scheme, who will provide the root certificate for software developer? Chip vendor such as nxp or the OEM?

Thanks!

Wenchuan

Re: LPC55xx certificate：why so many RoT keys?

ZhangJennie — Wed, 05 Jun 2019 10:04:34 GMT

Certification is not provided by nxp. it is generated by on chip application developer. OpenSSL is a good tool to generate certification.

Have a great day,
Jun Zhang

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Re: LPC55xx certificate：why so many RoT keys?

wilsonyan2019 — Tue, 11 Jun 2019 01:43:40 GMT

Thanks a lot!

Wenchuan

Re: LPC55xx certificate：why so many RoT keys?

ZhangJennie — Tue, 11 Jun 2019 02:43:55 GMT

You are welcome.

Have a great day,
Jun Zhang

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