Page 219 - DCAP403_Operating System
P. 219

Operating System




                    Notes          When PGP is first installed, the user has to create a key-pair. One key, the public key, can be

                                   advertised and widely circulated. The private key is protected by use of a passphrase. The
                                   passphrase has to be entered every time the user accesses their private key.

                                                             Box 11.1: A PGP Signed Message
                                     -----BEGIN PGP SIGNED MESSAGE-----
                                     Hash: SHA1
                                     Hi Carol.
                                     What was that pithy Groucho Marx quote?
                                     /kess
                                     -----BEGIN PGP SIGNATURE-----
                                    Version: PGP for Personal Privacy 5.0
                                     Charset: noconv
                                    iQA/AwUBNFUdO5WOcz5SFtuEEQJx/ACaAgR97+vvDU6XWELV/GANjAAgBtUAnjG3
                                     Sdfw2JgmZIOLNjFe7jP0Y8/M
                                     =jUAU
                                     -----END PGP SIGNATURE-----
                                   Box 11.1 shows a PGP signed message. This message will not be kept secret from an eavesdropper,
                                   but a recipient can be assured that the message has not been altered from what the sender
                                   transmitted. In this instance, the sender signs the message using their own private key. The
                                   receiver uses the sender’s public key to verify the signature; the public key is taken from the
                                   receiver’s keyring based on the sender’s e-mail address.




                                      Note    The signature process does not work unless the sender’s public key is on the
                                     receiver’s keyring.

                                                            Box 11.2: A PGP Encrypted Message
                                     -----BEGIN PGP MESSAGE-----
                                     Version: PGP for Personal Privacy 5.0
                                     MessageID: DAdVB3wzpBr3YRunZwYvhK5gBKBXOb/m
                                     qANQR1DBwU4D/TlT68XXuiUQCADfj2o4b4aFYBcWumA7hR1Wvz9rbv2BR6WbEUsy
                                     ZBIEFtjyqCd96qF38sp9IQiJIKlNaZfx2GLRWikPZwchUXxB+AA5+lqsG/ELBvRa
                                     c9XefaYpbbAZ6z6LkOQ+eE0XASe7aEEPfdxvZZT37dVyiyxuBBRYNLN8Bphdr2zv
                                     z/9Ak4/OLnLiJRk05/2UNE5Z0a+3lcvITMmfGajvRhkXqocavPOKiin3hv7+Vx88
                                     uLLem2/fQHZhGcQvkqZVqXx8SmNw5gzuvwjV1WHj9muDGBY0MkjiZIRI7azWnoU9
                                     3KCnmpR60VO4rDRAS5uGl9fi oSvze+q8XqxubaNsgdKkoD+tB/4u4c4tznLfw1L2
                                     YBS+dzFDw5desMFSo7JkecAS4NB9jAu9K+f7PTAsesCBNETDd49BTOFFTWWavAfE
                                     gLYcPrcn4s3EriUgvL3OzPR4P1chNu6sa3ZJkTBbriDoA3VpnqG3hxqfNyOlqAka
                                     mJJuQ53Ob9ThaFH8YcE/VqUFdw+bQtrAJ6NpjIxi/x0FfOInhC/bBw7pDLXBFNaX
                                     HdlLQRPQdrmnWskKznOSarxq4GjpRTQo4hpCRJJ5aU7tZO9HPTZXFG6iRIT0wa47
                                     AR5nvkEKoIAjW5HaDKiJriuWLdtN4OXecWvxFsjR32ebz76U8aLpAK87GZEyTzBx
                                     dV+lH0hwyT/y1cZQ/E5USePP4oKWF4uqquPee1OPeFMBo4CvuGyhZXD/18Ft/53Y
                                     WIebvdiCqsOoabK3jEfdGExce63zDI0=
                                     =MpRf
                                     -----END PGP MESSAGE-----




          212                              LOVELY PROFESSIONAL UNIVERSITY
   214   215   216   217   218   219   220   221   222   223   224