SQL ID/PK obfuscation - generate a random integer sequence to conceal row count?

I am asking this on here as it doesn't seem to be a question with an obvious or easily-found answer.

The situation is that I am building an application in MySQL/PHP (Yii2 framework) to be used by an employment agency. I think it is general interest to hide both the number of candidates and vacancies in the database i.e. I don't want someone being able to work out there is 5, 50 or 500 candidates and the same with vacancies. So I am basically looking to obfuscate the number of records in that table.

I am thinking about using a 10-digit randomly generated integer for this purpose, and using EXISTS to verify the uniqueness of the sequence prior to creating the record.

I would like to here from people who may have a better understanding than me regarding this as it's obviously not a simple or common scenario. So any insight would be greatly appreciated.