I still know my Starcraft CD key to this day as well.

Bonus: The same key also works for Half-Life. They used the same algorithm.

I loved quake iii and similar properties that only checked the last digit, 3 or c

You can use classic starcraft / brood war keys as vouchers on battle.net if you want to verify and make sure you'll always have a digital copy available :)

The game has been free to play for years now, so you might need an old disc image to get at the checksum algorithm :).

One of the original starcraft games accepts 11111-...-11113 (I don't remember how many places, but all 1's and then a 3 or 4).

Guess how I figured that one out.

Brood War didn't come with a CD-key, only the original StarCraft disc did =)

Yeah it was one of the disks, I always installed them in tandem.

Scott? Is that you?