Hypothetical situation: This is a situation that is depicted based on imagination.
The author gave a hypothetical situation of Alice encrypting a message to bob using Bob's public key and Bob decrypting the message on his own end using his own private key.
Example
The author cited an example that Alice cannot afford to encrypt a hundred messages one by one due to the long time it takes. This is to back up the point earlier stated that encrption and decyption take time for long. messages.
Fact: This a point that is generally true
The point that encryption and decryption can take several minutes on a personal computer if the message is long is a fact
