Restricting search on index

Hi Team,
We are using Standard Elastic cloud license to host our data with ES version 6.8.
We are planning upgrade the ES version to 7.x soon.
We have an upcoming requirement to ingest a new set of data that should not be searchable with the current data.

Could you please let us know the best approach to safely store this data so that it will not be made available in search in a normal API call.

We wanted to know the best possible options with Standard ES cloud license.

With Elastic Cloud you get access to a heap of access control features.

Take a look at https://www.elastic.co/guide/en/cloud/current/ec-security.html.