Today I read the first time about a draft of
TCP Stealth which should serve as a protection against GCHQ and NSA vulnerability scanning(Source: https://en.wikipedia.org/wiki/TCP_Stealth):
The proposal modifies the TCP three-way handshake by only accepting connections from clients that transmit a proof of knowledge of a shared secret. If the connection attempt does not use TCP Stealth, or if authentication fails, the server acts as if no service was listening on the port number. (Source: https://en.wikipedia.org/wiki/TCP_Stealth)
* What are the differences between TCP Stealth and Single Packet Authorization?
* What are the advantages of TCP Stealth compared to Single Packet Authorization?