olemus
salajane võti krüpteerimiseks
TLS protokollikliendi ja protokolliserveri vahel

RFC 5246:
ühenduse kahe võrdpartneri 48-baidine ühissaladus
= a 48-byte secret shared between the two peers in the connection

ülevaateid
https://crypto.stackexchange.com/questions/27131/differences-between-the-terms-pre-master-secret-master-secret-private-key

https://www.cryptologie.net/article/340/tls-pre-master-secrets-and-master-secrets/

TLS standard
https://tools.ietf.org/html/rfc5246