
Information Security ◾ 363
and owner integrity (see Figure12.7). e idea here is for Jane to append a
second part, known as a digital signature and denoted “sig” in the gure. A
digital signature is just an abbreviated digest of the plaintext that has been
encrypted with Jane’s private signature. e complete ciphertext consists
of the encrypted plaintext together with the digital signature encrypted
with the public key of the intended recipient (Jose).
Figure12.7 also illustrates how security is maintained. e rst step
upon message receipt is to decrypt the ciphertext using Jose’s private key.
As described earlier, this ensures conden ...