Searching for suiting index

Hi,
 
I store around 300 bits the row in my table. Every bit is a boolean values on its own.
I want to do a similarity search by comparing each bit and get every row which has a certain number of equal bits.
What kind of index could be useful for scenario?
Could it make sense to calculate a kind of hashvalue for each row to filter the rows dirty at first.
 
Thank you for your help
Janek Sendrowski