winsock chat authentication

how do i go around doing this need your help

this topic about client + server


server is listening for incomming connection request and accepts that connection then his ready to chat ok fine.

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now the main part

i wish to create some form of packet auth it can be any data sent to the server if some form of packet etc is matched then allow the connection or else disallow.

this is to prevent unauthorized connection request from people if they get hold of your ip and port.


i wish to know more from you how it will be best do secure it thanks.

has to be some sort of authenication , no registration auth , but some other packet auth