Assuming you have your random data pairs in columns A & B
Then in cell C1 type =1-ISNA(VLOOKUP(B1,A:A,0,FALSE))*1
and then copy this down the column for as many rows as you have pairs of random numbers in columns A and B
Then in say D1 put =SUM(C:C)=0
This will show true if all data is unique, or false if any value in column B matches any value in column A