The security consequence discussed in the draft is that since handshakes validate, allowing the protocol to bypass them undermines authentication, giving more o

The security consequence discussed in the draft is that since handshakes validate, allowing the protocol to bypass them undermines authentication, giving more opportunity to construct, say, man-in-the-middle attacks. There is no whitelist of algorithms. The discussion talks generally about how to patch up this authentication problem, but it doesn't go into much detail. Ignorance is really our default state when it comes to security.