Wikipedia text is now licensed under a CC BY SA 3.0 Unported license, which isn't the same as the license you're currently using for this document (CC BY 4.0 International). The SA part means that if you copy and include a substantial amount of text from Wikipedia, then you must license your entire document under the same CC BY SA license (i.e. the "SA" part makes it a viral license).
Maybe just link to the relevant section in Wikipedia?
There's a line that reads:
Wikipedia text is now licensed under a CC BY SA 3.0 Unported license, which isn't the same as the license you're currently using for this document (CC BY 4.0 International). The SA part means that if you copy and include a substantial amount of text from Wikipedia, then you must license your entire document under the same CC BY SA license (i.e. the "SA" part makes it a viral license).
Maybe just link to the relevant section in Wikipedia?
https://en.wikipedia.org/wiki/Transport_Layer_Security#TLS_handshake