Can someone explain how the RSA (blessed clients) works?

What prevents a man-in-the-middle attack?

I was talking on #crossfire and was asked how blessed clients work and how the
netrek community prevents people analyzing the client/server communication and
taking the client source (cow for instance) and spoofing the authentication.

I believe the public key is embedded in the binary and the private key is on the
metaserver, right?

What prevents a user from picking out the embedded key and using it (writing
some code) to make a borg client that masquarades as a blessed binary?

Bob Tanner <tanner at>         | Phone : (952)943-8700, Minnesota, Linux | Fax   : (952)943-8500, Minnesota, Wireless | Coding isn't a crime. 
Key fingerprint =  6C E9 51 4F D5 3E 4C 66 62 A9 10 E5 35 85 39 D9