I understand that PKI uses digital certificates to link a public key to an entity, but is there anything similar for symmetric cryptography.
If, theoretically, PKI didn't exist, how do you know you are sending your ciphertext to the right person?
Is the security in the fact that even if you are sending the encrypted text to the wrong person, they won't be able to read it as they don't have the secret key? Would this not be dangerous as they can attack the ciphertext?
For example, Alice wants to send an encrypted message to Bob. Is there anyway (without PKI) Alice can know that her ciphertext is reaching Bob, and not Chris, who is pretending to be Bob? Does she have to rely on the fact that Chris wouldn't know the key so it would be considered safe?
There are no 'digital certs' to be used in symmetric encryption to tie a user to an address for example.