Features of Public Key System in SET - I
Note that Merchants and Financial Organizations have separate asymmetric key-pairs for the “symmetric key-exchange” and digital signature process.
Note cardholders do not need a key exchange key-pair
Note digital signature certificates are exchanged in protocol and need not be known ahead of time whereas one must know the public key with which to encrypt the secret key
SET uses what they call a dual signature but which is really a signed double message
Often one needs to conduct a transaction where two parts are intrinsically linked e.g. An offer from Bob to Alice to buy her property and an authorization to the bank to transfer the funds
Bob wishes the offer to be seen by Alice but keep the bank authorization confidential