Use Besu-extended privacy
Hyperledger Besu provides an extended implementation of privacy allowing you to create a privacy group for a set of participants. You must specify the privacy group ID when sending private transactions.
To enable the PRIV API methods, use the --rpc-http-api or --rpc-ws-api command line options.
To create the privacy group containing the recipients of a private transaction, use priv_createPrivacyGroup.
To create an EEA-compliant private transaction, specify privacyGroupId when creating the signed transaction passed as an input parameter to eea_sendRawTransaction.
Privacy group type
Privacy groups created using priv_createPrivacyGroup have a BESU privacy group type when returned by priv_findPrivacyGroup.
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": [
    {
      "privacyGroupId": "GpK3ErNO0xF27T0sevgkJ3+4qk9Z+E3HtXYxcKIBKX8=",
      "name": "Group B",
      "description": "Description of Group B",
      "type": "BESU",
      "members": [
        "negmDcN2P4ODpqn/6WkJ02zT/0w0bjhGpkZ8UP6vARk=",
        "g59BmTeJIn7HIcnq8VQWgyh/pDbvbt2eyP0Ii60aDDw="
      ]
    }
  ]
}