My online game currenty uses winsock2 for all the data transfer needs. I have decided I need to protect the information traveling. My question is.... how much of a performance impact would a game take by using ssl? openssl to be exact. The game is a fast paced online boxing game so data is being transmited very rapidly.... As for as I can tell the only speed loss occurs on initial connect when it goes through the entire "handshake"... Is there also a signficant speed loss during the actual sending and receiving? Any thoughts on this would be greatly appreciated...

There is not significant speed loss during transmit/receive for current CPUs (the encryption isn't that heavy).

However, SSL/OpenSSL use TCP, which is not well suited for a low-latency game.

Also, what are you protecting the data against? The players have access to the un-encrypted data on their machines; they can attach to memory and poke around wherever they want. In fact, that's what many game cheats do.