olemus
TLS-kätluse käigus kliendi loodud
salajane võti põhisaladuse arvutamiseks
= the secret key generated by the client during the TLS handshake to calculate the master secret

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

https://crypto.stackexchange.com/questions/24780/what-is-the-purpose-of-pre-master-secret-in-ssl-tls/24783

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