Cryptography, Perfect Secrecy and One Time Pads | Two Minute Papers #25

Cryptography helps us to communicate securely with someone in the presence of third parties. We use this when we do for instance, online banking or even as mundane tasks as reading our gmail. In this episode, we review some cipher techniques such as the Caesar cipher, rot13, and as we find out how easy they are to break, we transition to the only known technique to yield perfect secrecy: one time pads. Are they practical enough for everyday use? How do our findings relate to extraterrestrial communications? Both questions get answered in the video. Additional comment: "In modern certification cryptanalysis, if a cipher output can be distinguished from a PRF (pseudo random functions), it's enough to deem it broken." - Source: https://twitter.com/cryptoland/status/666721478675668993 ______________________ The paper "Cipher printing telegraph systems: For secret wire and radio telegraphic communications" is available here: http://math.boisestate.edu/~liljanab/Math509Spring10/vernam.pdf You can try encrypting your own messages on these websites: http://practicalcryptography.com/ciphers/caesar-cipher/ http://rot13.com/index.php http://www.braingle.com/brainteasers/codes/onetimepad.php Subscribe if you would like to see more of these! - http://www.youtube.com/subscription_center?add_user=keeroyz The thumbnail background was created by Adam Foster (CC BY 2.0) - https://flic.kr/p/b99vsi Splash screen/thumbnail design: Felícia Fehér - http://felicia.hu Károly Zsolnai-Fehér's links: Patreon → https://www.patreon.com/TwoMinutePapers Facebook → https://www.facebook.com/TwoMinutePapers/ Twitter → https://twitter.com/karoly_zsolnai Web → https://cg.tuwien.ac.at/~zsolnai/