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BQ40Z80: bqKey Programmer Software Programming Failure -Elliptic Curve Cryptography (ECC)

Part Number: BQ40Z80
Other Parts Discussed in Thread: BQKEYPROGRAMMER

Hi,

We're using the bqKey Packager and bqKeyProgrammer software to program BQ40Z80 ICs with an ECC key but are getting the below error.

A few seconds after attempting to program the key, the error "Key Programming Failed!" is displayed with the comment "Validating ECC challenge response failed. Retry this operation" at the bottom of the window:

These are the settings we're using to generate the key (example values used as we do not wish to share the actual keys!):

This seems to follow the guidelines set out in SLUUBU3 but we're not able to get the key programmed onto the BQ40Z80? We have managed to use this software to program an SHA-1 key but we need to use the more secure ECC option.

We've tried both the 4800_0_04 firmware and the 4800_0_02 firmware on the BQ40Z80 with no luck. We've also tried multiple BQ40Z80 ICs with the same result. Are there any other steps that we're missing that aren't detailed in SLUUBU3 document - it's not particularly detailed?  

Also please could you confirm the software does work with the BQ40Z80 on both 4800_0_04 firmware and the 4800_0_02 firmware? When opening the software the word 'TEST' is displayed - is this still development software, is it fully functional?

Thank you in advance. The rest of the fuel gauge seems to be working well, we'd just like to add this final authentication feature.

Thanks

Matt

  • Hello Matt,

    The software is fully functional. The Test designation means that it is used for testing the feature.

    ECC key pairs need to be generated using the specified ECC key pair generation procedure. The programmer will program in the keys as specified. If the key pair was not generated correctly, then validation typically fails.

  • Hi Shirish, Thank you for your response - it is very helpful. Do you have any documentation on the ECC key pair generation procedure?  I see there's a release note mentioned in section15.3 of the technical reference? I've tried generating ECC pairs with various online generators but am unsure if there is a specific curve that needs to be used for the BQ40Z80 as I'm still getting the same fault code? Unfortunately looking up "EC-KCDSK" online doesn't return many results.  Do you have any sample key pairs  so we can try programming a known good key pair to check our setup? Thank you for your help.

  • Hello MAtt,

    I believe NIST website has the information but i am not familiar with the details.