16.3.1 Public-Private Key Pairs

As part of a PKI, public–private key pairs can be used to securely transmit shared secret keys through KEM and to digitally sign messages with DSA (see Figure 4). The public key 𝑃𝑘(2) of Client 2 encapsulates the shared secret key of Client 1, which can only be viewed by Client 2 using their private key 𝑆𝑘(2) to reverse the encapsulation. Client 1 uses their private key 𝑆𝑘(1) to digitally sig...