I have a 128 bit Pre-Shared Key. I don't want to use it directly. I'd much rather generated a session key with
HKDF(PSK, SALT) = SESSIONKEY.
I'm however under strict size limits for packet size. So I'm looking at the option of a 12 byte (96 bit) salt.
Does this significantly weaken my 128 bit PSK down to 96 bit? What is the true complexity of the resulting
SESSIONKEY? I don't think I get to combine them into something greater than 128bit because the salt (derivation seed) will be transmitted in the clear for the other side to use.