In the context of using PKI, when Sven wishes to send a secret message to Bob, he looks up
Bob’s public key in a directory, uses it to encrypt the message before sending it off. Bob then uses
his private key to decrypt the message and reads it. No one listening on can decrypt the message.
Anyone can send an encrypted message to Bob but only Bob can read it. Thus, although many
people may know Bob’s public key and use it to verify Bob’s signature, they cannot discover Bob’s
private key and use it to forge digital signatures.
What does this principle refer to?

A.
Irreversibility

B.
Non-repudiation

C.
Symmetry

D.
Asymmetry

Explanation:
PKI uses asymmetric key pair encryption. One key of the pair is the only way to
decrypt data encrypted with the other.