some vs. certain

[azz]

a. We had to publish those documents so that some people would believe us.
b. We had to publish those documents so that certain people would believe us.

Do either of these imply that there were already some people who believed us before we published those documents? Could they be used if prior to out publishing them nobody believed us?

And could (a) be used if the speaker had a specific set of people in mind?


Many thanks.

[Alan]

(Not grammar, but...)

'Certain' implies that the speaker/writer is aware of, but unwilling to disclose, the identity of the persons concerned.