1 00:00:00,760 --> 00:00:03,670 Pretty Good Privacy, also know as PGP, 2 00:00:03,670 --> 00:00:05,760 is an encryption program that's used for signing, 3 00:00:05,760 --> 00:00:08,000 encrypting, and decrypting emails. 4 00:00:08,000 --> 00:00:11,130 Over the years, PGP's use has expanded beyond emails, 5 00:00:11,130 --> 00:00:13,850 though, and includes an entire suite of protocols 6 00:00:13,850 --> 00:00:17,790 that can encrypt emails, files, and even entire hard disks. 7 00:00:17,790 --> 00:00:21,050 PGP uses an older algorithm, though, known as IDEA, 8 00:00:21,050 --> 00:00:24,120 which you may remember from our symmetric algorithm lesson. 9 00:00:24,120 --> 00:00:26,910 Now you may be wondering, why didn't I just cover PGP 10 00:00:26,910 --> 00:00:29,750 all the way back in the symmetric algorithm lesson then? 11 00:00:29,750 --> 00:00:33,250 Well, PGP is actually a hybrid cryptographic tool 12 00:00:33,250 --> 00:00:35,040 because it uses a symmetric cipher 13 00:00:35,040 --> 00:00:38,390 for the bulk data encryption, but it uses RSA, 14 00:00:38,390 --> 00:00:41,520 an asymmetric cipher, to create the digital signatures used 15 00:00:41,520 --> 00:00:44,030 in signing its emails and to send the session keys 16 00:00:44,030 --> 00:00:45,700 over an un-trusted network. 17 00:00:45,700 --> 00:00:47,160 This is what I meant before when I said 18 00:00:47,160 --> 00:00:50,200 that we often combine both symmetric and asymmetric ciphers 19 00:00:50,200 --> 00:00:53,030 to give us a hybrid approach or implementation. 20 00:00:53,030 --> 00:00:56,020 Now PGP uses key sizes of 128 bits 21 00:00:56,020 --> 00:00:58,760 or more for symmetric functions and key sizes 22 00:00:58,760 --> 00:01:03,140 between 512 bits and 2,048 bits for its asymmetric function. 23 00:01:03,140 --> 00:01:06,480 Over time, PGP became an open source encryption cipher, 24 00:01:06,480 --> 00:01:08,790 and as such, it was able to be forked and used 25 00:01:08,790 --> 00:01:10,100 for further development. 26 00:01:10,100 --> 00:01:12,320 The result of that was GPG. 27 00:01:12,320 --> 00:01:14,690 This stands for the GNU Privacy Guard, 28 00:01:14,690 --> 00:01:16,590 and it's an implementation of cryptography 29 00:01:16,590 --> 00:01:18,920 that's used to provide you with confidentiality in your data 30 00:01:18,920 --> 00:01:21,200 by encrypting it like PGP did. 31 00:01:21,200 --> 00:01:24,840 Now, GPG is actually a newer version of PGP, 32 00:01:24,840 --> 00:01:27,500 or the Pretty Good Privacy encryption suite. 33 00:01:27,500 --> 00:01:31,770 The newer GPG uses the more modern AES encryption algorithm 34 00:01:31,770 --> 00:01:34,680 instead of that weaker IDEA symmetric algorithm. 35 00:01:34,680 --> 00:01:36,760 Now GPG is a freely available 36 00:01:36,760 --> 00:01:39,310 and non-patented encryption solution that's available 37 00:01:39,310 --> 00:01:42,140 for Linux, Windows, and Macintosh operating systems. 38 00:01:42,140 --> 00:01:43,810 So if you're looking for one to try out, 39 00:01:43,810 --> 00:01:46,423 you can download GPG and get started today.