KAS-ECC Revision Sp800-56Ar3 fixedInfoPartyU and fixedInfoPartyV are missing?

[ylu0926]

KAS-ECC Revision Sp800-56Ar3 fixedInfoPartyU and fixedInfoPartyV are missing?

In ACVP KDA TwoStep KDA uPartyInfo and vPartyInfo are clearly included. So iut knows how to construct the fixedInfo.
But, there are no fixedInfoPartyU and fixedInfoPartyV are given in ACVP KAS ECC SP800-56Ar3 JSON test case. We are very confused about that.

When the following information are given, we do not clearly know what is used as the uPartyInfo and what is used as the vPartyInfo? And finally, what will the fixedinfo be?

{
"scheme": "ephemeralUnified",
"kasRole": "initiator",
"l": 512,
"iutId": "A1B2C3D4E5",
"serverId": "1234567890"

            "fixedInfoPattern": "algorithmId||l||uPartyInfo||vPartyInfo",
            "fixedInfoEncoding": "concatenation",

}
{
"ephemeralPublicServerX": "D82BF11DF13099B29A202A16164CFCC886D9F3379872D81DD242BD45",
"ephemeralPublicServerY": "998ADDF1842E863D80419D26D8C17A1E7B0561BAFBFBE7F9DB79645A",
"ephemeralPrivateIut": "16EBCF989415F3E864E2E24D4E46E0C0435239471352A96DFB3903B9",
"ephemeralPublicIutX": "E90B9175D19B14DD90BE3CA4613E316FA11CD13821052475FEC5CDAB",
"ephemeralPublicIutY": "00A20BB68E0FB75FF8E7FE9DC2FCAFAB36495428239FD312DF7A78EC",
"tcId": 1,
"kdfParameter": {
"kdfType": "twoStep",
"salt": "00000000000000000000000000000000000000000000000000000000",
"algorithmId": "3B9456AE"
},

My understanding is that the uPartyInfo is the "serverId" and the vPartyInfo is the "iutId".
So the final fixedinfo would be
"algorithmId||l||uPartyInfo||vPartyInfo",= "3B9456AE000002001234567890 A1B2C3D4E5”
Here :
"algorithmId": "3B9456AE"
“l’: “00000200” 512 as 32 bits
“uPartyInfo”= "serverId": "1234567890"
“vPartyInfo”= "iutId": "A1B2C3D4E5",

Or the uPartyInfo needs to include server public key?
Thanks.

[jbrock24]

Hi @ylu0926 - The fixedinfopattern is described in section 7.5.1.3 of the spec SP800-56Ar3. - this includes details on v/uPartyInfo's. Please let me know if this section doesn't answer your question(s), and I will try to help out further. Thanks!