LPC55xx certificate：why so many RoT keys?

[wilsonyan2019]

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

[ZhangJennie]

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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[wilsonyan2019]

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

[ZhangJennie]

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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[wilsonyan2019]

Thanks a lot!

Wenchuan

[ZhangJennie]

You are welcome.

Have a great day,
Jun Zhang

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