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During the American Civil War (1861-65), both the Union and the Confederacy used a variety of codes and ciphers to protect vital communications - with varying degrees of success. In this episode, we look at some of the most common systems used by both sides.

0:00 Introduction
1:26 Private Internet Access VPN Sponsor Segment
3:08 Jefferson Wheel Cipher/M-94
7:42 Difference Between Codes and Ciphers
10:18 Stager Route Cipher
15:24 Confederate Substitution Ciphers
16:39 Vigenere Cipher
18:15 Confederate Cipher Cylinder/Disk
19:40 Cryptanalysis of Vigenere Cipher
22:30 One-Time Pad Ciphers
23:13 Book/Dictionary Codes
24:09 Grille Ciphers
26:41 Outro

SOURCES:

https://ww2.amstat.org/mam/06/Sauerberg_route-essay.html 
http://www.c3teachers.org/wp-content/uploads/2016/01/ExplainerCipherintheCivilWar-Final.pdf
https://cryptiana.web.fc2.com/code/civilwar0.htm
https://www.monticello.org/research-education/thomas-jefferson-encyclopedia/wheel-cipher/
https://www.cryptomuseum.com/crypto/usa/ccd/index.htm
https://lincolnconspirators.com/2019/07/26/john-wilkes-booths-confederate-cipher/
https://cryptiana.web.fc2.com/code/civilwar5.htm#SEC2
https://cryptiana.web.fc2.com/code/civilwar4.htm
https://cryptiana.web.fc2.com/code/civilwar6.htm