Despite its respectable age (the first specification was published in September 1981), TCP is still alive and researches and IETFers continue to develop new extensions to improve the protocol. Multipath TCP received a lot of attention during the last years. Another TCP extension to improve the security of TCP has been submitted for the next IETF meeting. TCP crypt aims at improving the security of TCP by allowing the utilisation of crypto mechanisms to protect the TCP segments. In a sense, TCP crypt is similar to combining TCP with SSL, but there are subtle and importance differences between SSL/TLS and TCP crypt that are discussed in the original TCP crypt paper presented at USENIX Security 2010.