1800-1899
- 1809-14 George Scovell's work on Napoleonic ciphers during the Peninsular War
- 1831 - Joseph Henry proposes and builds an electric telegraph
- 1835 - Samuel Morse develops the Morse code
- 1854 - Charles Wheatstone invents Playfair cipher
- c. 1854 - Babbage's method for breaking polyalphabetic ciphers (pub 1863 by Kasiski)
- 1855 - For the English side in Crimean War, Charles Babbage broke Vigenère's autokey cipher (the 'unbreakable cipher' of the time) as well as the much weaker cipher that is called Vigenère cipher today. Due to secrecy it was also discovered and attributed somewhat later to the Prussian Friedrich Kasiski.
- 1883 - Auguste Kerckhoffs' La Cryptographie militare published, containing his celebrated laws of cryptography
- 1885 - Beale ciphers published
- 1894 - The Dreyfus Affair in France involves the use of cryptography, and its misuse, in regard to false documents.
Read more about this topic: Timeline Of Cryptography