Which sentence is most relevant to the argument that Zimmermann’s PGP was easy to use? By this stage, sending a PGP encrypted message is becoming quite complicated.
The IDEA cipher is being used to encrypt the message, RSA is being used to encrypt the IDEA key, and another stage of encryption has to be incorporated if a digital signature is required.
To send a message to Bob, Alice would simply write her e-mail and select the PGP option from a menu on her computer screen.
Nothing in PGP was original—Diffie and Hellman had already thought of digital signatures and other cryptographers had used a combination of symmetric and asymmetric ciphers to speed up encryption . . .