Use of multiple caches per page.

I want to be able to cache various pages, all called index.php but
have various GET parameters for example like...

index.php?a=1

index.php?a=2&b=3

index.php?a=1&b=2&c=4

Can I store these the strings of GET parameters as the cache_id's to
cache the various permutations of pages? (something like... cache_id =
"a=1&b=2&c=4")