A way to provide strong encryption in an SSL connection with older Web browsers that support keys only up to 64 bits in length. If the server supports server-gated cryptography (SGC), it returns an SGC digital certificate to the Web browser, known as a "SuperCert," "Global-Server-ID" or "HyperSign." The SGC certificate instructs the Web browser to perform a follow-up handshake to establish keys of 128 bits and higher (for details of the SSL handshake, see
SSL).
It Used to Be Illegal
Prior to 2000, it was illegal for U.S. companies to export software that used encryption greater than 64 bits; however, financial organizations were permitted stronger ciphers, and server-gated cryptography was installed in the Web servers of those institutions. Subsequently, browsers support longer keys, and SGC is only useful with older browsers. See
SSL.