SSDI Used for Deceased Children

A legitimate concern over the public nature of the SSDI is that some individuals have used number of deceased children to get tax deductions. This seems to be a relatively simple problem to solve:

• If the number of the child has been used for exemptions before, the SSN of the person claiming the child should be a number filed on a return with the child's SSN in the past. If the child's number and parent's number have not been on the same return in a previous year, the return should be immediately flagged. 
• The first time the child's number is used, there should be some protocol.

I'm not exactly certain of the execution of this idea, but it seems relatively easy to me that SSN numbers that have been used before should be on returns with at least one of the same parent numbers as in past returns.